---
title: "Shopify Fitment Apps: How to Choose a Year, Make, Model App"
url: https://www.uncap.com/post/shopify-automotive-fitment-apps
author: "Denis Dyli"
published: 2026-07-24
updated: 2026-11-13
summary: "A Shopify fitment app adds Year, Make, Model search so buyers pick a vehicle and see only the parts that fit before buying. Apps differ most in their data: some expect a hand-maintained spreadsheet, others import ACES fitment and PIES product files, and large catalogs need validated bulk import and coverage reporting. For B2B parts sellers on Shopify, filtered results must also show each company's catalog price and real stock, which means testing as a logged-in B2B buyer and syncing inventory from the ERP. Uncap Garage imports ACES/PIES or your own data, saves the buyer's vehicle and filters catalog, search and collections."
---

# Shopify Fitment Apps: How to Choose a Year, Make, Model App

> A Shopify fitment app adds Year, Make, Model search so buyers pick a vehicle and see only the parts that fit before buying. Apps differ most in their data: some expect a hand-maintained spreadsheet, others import ACES fitment and PIES product files, and large catalogs need validated bulk import and coverage reporting. For B2B parts sellers on Shopify, filtered results must also show each company's catalog price and real stock, which means testing as a logged-in B2B buyer and syncing inventory from the ERP. Uncap Garage imports ACES/PIES or your own data, saves the buyer's vehicle and filters catalog, search and collections.

A Shopify fitment app adds Year, Make, Model (YMM) search to your store, so a buyer picks a vehicle and sees only the parts that fit it before buying. The apps differ less in the selector than in the data behind it: some expect a spreadsheet you maintain by hand, others import ACES and PIES files, and B2B sellers also need each account's pricing to carry through the filter.

This guide covers what a [Year, Make, Model](/glossary/year-make-model) fitment app does, which data it needs, the features worth checking, and how to choose for a parts catalog that sells to repair shops, dealers and enthusiasts on the same Shopify store.

## What a Shopify fitment app adds

[Fitment](/glossary/fitment) is the record of which vehicles a part fits. A fitment app turns that record into a shopping experience. Shopify's built-in search matches products on fields such as title, tags, vendor, SKU and barcode. A part that fits 40 vehicles is a relationship between one product and many vehicles, and a fitment app is what stores and filters that relationship.

Most fitment apps for Shopify add the same building blocks:

- A vehicle selector. Dropdowns for year, make and model, sometimes with engine, submodel or trim, on the home page, collection pages and search.
- A saved vehicle. Often called a garage: the buyer saves a vehicle once and the store remembers it on the next visit.
- Catalog filtering. Collections and search results narrow to parts that fit the selected vehicle.
- Product page confirmation. A fits or does not fit message on each product, so the buyer knows before adding to cart.
- Fitment data management. A way to import, edit and check which products map to which vehicles.

Some apps also offer lookup by vehicle identification number (VIN) instead of dropdowns. Treat VIN lookup as a feature to confirm in the demo, along with what it costs, since decoding a VIN depends on a vehicle data source behind the app.

The selector is the easy part to judge from a demo store. The data model and how it holds up on your catalog decide whether the app still works a year after launch.

## Fitment data: spreadsheet or ACES and PIES

Every fitment app runs on data, and where yours comes from narrows the field quickly.

Uncap's Garage product page describes the two standards this way: "ACES (Aftermarket Catalog Exchange Standard) and PIES (Product Information Exchange Standard) are the auto care industry's standards for vehicle fitment data and product information." Fitment can reach your store as ACES fitment files with PIES product data, or as a spreadsheet you keep yourself.

That gives you two questions for any app:

- Can it import what you have? If you receive ACES files from suppliers, check that the app imports them directly rather than asking you to convert them to a custom spreadsheet first. If your fitment lives in a spreadsheet, check the import template and how it handles one part that fits many vehicles.
- Can you keep it current? Fitment changes as parts are superseded, discontinued or sourced from a new supplier. Ask how updates are imported, whether a re-import overwrites manual fixes, and whether you can see which products have no fitment mapped yet.

Universal parts need their own handling. A wiper blade or an oil filter can fit dozens of vehicles, and a part that fits nearly everything should not need thousands of hand-entered rows. Ask how the app marks universal or broad-fit products.

Our explainer on [ACES and PIES fitment data standards](/post/aces-pies-fitment-data-standards) covers the file formats in more detail.

## Catalog size changes what you need

A store with a few thousand parts and one clean spreadsheet has different needs from a distributor with hundreds of thousands of SKUs and fitment arriving from many suppliers.

For a small catalog, the deciding factors are usually ease of setup, a clear import template and a selector that looks right in your theme. Most of the work is entering the data once.

For a large catalog, the data operation becomes the product. Look for:

- Bulk import that validates. Errors should be reported row by row, not discovered by buyers.
- Coverage reporting. You need to see which products are mapped, which are missing fitment, and which vehicles have gaps.
- Search at scale. Filtering has to stay fast when one vehicle maps to tens of thousands of parts.
- One record for every surface. The same fitment should drive product pages, search and collections, so they never disagree.

Get pricing for your real SKU count and fitment row count, not the demo store's.

If you are moving an existing parts store to Shopify, read [how to migrate an auto parts store without losing fitment data](/post/migrating-auto-parts-store-shopify-fitment-data) before you choose, because the import format decides how much cleanup the move needs.

## Why B2B account pricing has to survive the filter

Parts sellers who sell to repair shops, dealers and fleets as well as retail buyers have a second job. For them, filtering by vehicle is half the job. The other half is showing each account its own price on the filtered results.

On Shopify B2B, prices come from catalogs. Shopify's help center says: "You set prices and product availability by assigning the appropriate catalogs to companies and company locations." Shopify B2B runs on the Basic, Grow, Advanced and Plus plans, with up to 3 active catalogs across all your B2B markets below Plus and unlimited B2B market catalogs on Plus.

So the check is simple. Log in as a test B2B buyer, select a vehicle, and confirm the filtered products show that company's catalog price, quantity rules and availability, not the retail price.

Here is a hypothetical example of why it matters. A distributor sells brake parts to two repair shops. Both search for the same pickup truck. One shop has negotiated pricing on brake work; the other is a new account on standard pricing. If the fitment filter and the price come from the same Shopify B2B catalogs, each shop sees the right parts at its own price. If they do not, the negotiated account either orders and waits for a price correction or calls in, and the self-service catalog stops saving anyone time.

Stock matters the same way. A part that shows as a fit but is out of stock at the buyer's usual location is a promise the store cannot keep. Where your ERP owns inventory, [Uncap Connect](/products/connect) keeps inventory, orders, customers and pricing in real-time, two-way sync between Shopify and the ERP, so fitment and stock tell the same story.

## Features to check before you choose

Use this checklist in every demo, on your own data where the vendor allows it.

- Selector depth. Year, make and model only, or also engine, submodel and trim? Engine and trim matter when the same model takes different parts.
- Saved vehicles. Does the vehicle persist across pages and visits? Can a signed-in buyer, such as a fleet or shop, keep several vehicles?
- Fits badges. Does every product and variant show whether it fits the selected vehicle?
- Data import. ACES, PIES, your spreadsheet, or all three? How are updates and supersessions handled?
- Universal parts. Can broad-fit products be marked once instead of mapped vehicle by vehicle?
- Coverage view. Can you see what is mapped and what is missing?
- B2B pricing. Do filtered results show each company's catalog price on Shopify B2B?
- VIN lookup. Offered or not, and on which plan?
- Theme fit and speed. How does the selector get into your theme, what does it load on every page, and how does it affect page speed?
- Support and ownership. Who fixes a bad import at month end, and how fast?

## Choosing between an app and a custom build

Most stores should start with an app. A fitment app gives you a tested selector, data import and storefront filtering without building and maintaining your own.

A custom build makes sense in narrower cases: a catalog structure no app models well, fitment rules that depend on data only your systems hold, or a storefront where vehicle search has to work with other custom logic. Compared with an app, the cost is ongoing ownership: every Shopify theme change, data change and new vehicle year becomes your team's work. Shopify's help center describes a custom app as "an app that you or a developer builds exclusively for your Shopify store," and notes that "If you need help creating custom apps for your store, then you can hire a Shopify Partner."

Between the two sits a third option: a fitment app for the vehicle data and storefront, connected to the systems that own pricing and stock. On the fitment side, [Uncap Garage](/products/garage) lets you "Import ACES/PIES or your own data and map every product to the vehicles it fits." Shoppers save their vehicle (Year, Make, Model, engine) and keep it across visits, Year/Make/Model narrows catalog, search and collections, fits and doesn't-fit badges show on every product and variant, and a coverage console shows what is mapped and what is missing.

## Fitment in practice: Kooks Headers and Exhaust

Kooks Headers and Exhaust shows what fitment looks like when it is part of the whole store rather than a widget. Per [the Kooks case study](/work/kooks), Uncap replatformed the business onto one Shopify store for B2B and D2C.

The case study says Shopify was integrated with Kooks' Infor Visual ERP and a product information system, "enabling real-time inventory synchronization and vehicle-fitment search by year, make, model, and engine." Wholesale buyers got secure B2B portals with custom pricing, account management, self-service and reordering. The reported results were a 22% conversion rate uplift and a 38% reduction in total cost of ownership.

The useful lesson for anyone choosing a fitment app is where the search came from: the same ERP and product information integration delivered both real-time inventory and vehicle-fitment search. For more on how parts sellers run B2B and retail together, see our page on [auto parts and aftermarket ecommerce](/industry/auto-parts-aftermarket).

Dash Designs shows fitment as the start of a configurator. Buyers identify their vehicle by year, make and model, then choose seat position, style, fitment, material and color, and a custom Shopify app Uncap built resolves the exact SKU with its own images and pricing ([Dash Designs case study](/work/dashdesigns)).

## How to roll out fitment on your store

Step 1. Audit your data. Count SKUs, fitment rows, vehicles covered and products with no fitment.

Step 2. Pick the source of truth. Decide whether ACES files, a spreadsheet or your ERP owns fitment, and who updates it.

Step 3. Shortlist on the checklist above, and test each app with a sample of your hardest products: universal parts, trim-specific parts and superseded parts.

Step 4. Set up B2B pricing and stock sync before launch, then test as a logged-in B2B buyer and as a guest.

Step 5. Launch, then watch searches with no results, returns tagged wrong part, and products still missing fitment.

Step 6. Assign an owner for fitment data after launch. New model years, supersessions and new suppliers keep arriving, and the coverage report only helps if someone works through it every month.

Uncap is a Shopify Platinum Partner with 380+ storefronts launched on Shopify. If you want vehicle fitment, account pricing and ERP stock working as one store, [Talk to Our Experts](/quote).

## Frequently asked questions

### What is a Shopify fitment app?

A Shopify fitment app adds vehicle search to a parts store. Buyers pick a year, make and model, sometimes engine or trim, and the store filters products, search and collections to the parts that fit. Most apps also save the buyer's vehicle and show a fits or does not fit message on product pages.

### What data does a fitment app need?

A record of which vehicles each part fits. It can come as ACES fitment files with PIES product data, or as a spreadsheet you maintain. Check that the app imports the format you already have and lets you update it as parts are superseded.

### Does a fitment app work with Shopify B2B pricing?

It should, but test it. On Shopify B2B, prices come from catalogs assigned to companies and company locations. Log in as a B2B buyer, select a vehicle, and confirm the filtered results show that company's price and quantity rules rather than the retail price.

### Should I build custom fitment search or use an app?

Start with an app unless your catalog structure or fitment rules are something no app models well. A custom build means your team owns every theme change, data update and new model year. A third option is a fitment app connected to the ERP that owns pricing and stock.

### Do fitment apps support VIN lookup?

Some do. Decoding a vehicle identification number relies on a vehicle data source, so confirm whether VIN lookup is offered, on which plan, and whether your buyers need it before choosing on it.