Auto Parts and Accessories – The Aftermarket Supply Chain
What It Is
The auto parts and accessories market supplies components for vehicle repair, maintenance, customization, and enhancement. This is an aftermarket (see Article 11) that serves both professional installers (repair shops, dealers) and do-it-yourself (DIY) consumers.
Categories of Parts
OEM (Original Equipment Manufacturer) parts – Made by the same company that supplied the part when the vehicle was built. Sold in branded packaging (e.g., "Genuine Toyota Part"). Highest price, exact fit, manufacturer warranty.
OES (Original Equipment Service) parts – Made by the OEM supplier but sold under the supplier's own brand name, not the car brand. Same quality as OEM, lower price, no car brand markup. Example: A Bosch brake pad that is identical to what Bosch supplied to Mercedes, but in a Bosch box rather than Mercedes box.
Aftermarket parts – Made by third-party companies not involved in original vehicle production. Quality ranges from equal-to-OEM to very poor. Prices are typically lower than OEM.
Recycled (used) parts – Removed from salvaged vehicles. Lowest price, condition varies, availability uncertain.
Remanufactured parts – Used parts that have been disassembled, cleaned, inspected, and rebuilt to like-new condition (alternators, starters, transmissions). Mid-range price with warranty.
Distribution Channels
Parts reach buyers through multiple channels:
Dealership parts departments – Sell OEM parts to retail customers and to independent shops. Highest prices but fastest access to exact-fit parts.
Auto parts chains – Large retailers (AutoZone, O'Reilly, Advance Auto Parts, NAPA) serving DIY consumers and professional installers. Carry aftermarket and some OES parts.
Independent auto parts stores – Local businesses. May specialize in certain brands or vehicle types.
Online retailers – RockAuto, Amazon, eBay Motors. Wide selection, competitive prices, but shipping time and returns can be issues.
Wholesale distributors – Supply repair shops and dealers. Not open to the general public.
Junkyards and salvage yards – Sell used parts pulled from wrecked vehicles. Some have online inventory systems that search multiple yards simultaneously (car-part.com, Hollander).
The "Crash Parts" Market
Crash parts are body panels, bumpers, headlights, taillights, and other components damaged in collisions. This market is distinct because:
- Insurance companies often dictate part sourcing to control claim costs
- "Aftermarket crash parts" (non-OEM body panels) are common but fit and quality vary
- "CAPA certification" exists for aftermarket crash parts (Certified Automotive Parts Association)
- Some insurers require OEM parts for newer vehicles (e.g., less than 2 years old)
The Performance and Customization Market
Not all parts are for repair. The performance and customization market includes:
- Exterior modifications (wheels, body kits, spoilers, lighting)
- Performance parts (exhaust, intake, suspension, tuning chips)
- Interior accessories (seat covers, floor mats, infotainment upgrades)
- Utility accessories (roof racks, tow hitches, cargo carriers)
This market is largely decorative or performance-enhancing, not necessary for vehicle operation. Participants include enthusiasts, off-roaders, and vehicle owners who personalize their cars.
Availability and Speed
The parts market is described by:
Fill rate – Percentage of part requests that are in stock. Dealers and large chains strive for 85–95% fill rates.
Speed to customer – Same-day (in-store pickup), next-day (warehouse to store), or 2–5 days (online).
Discontinued parts – For older vehicles, OEM parts may no longer be produced. Buyers then rely on NOS (New Old Stock, unused parts from dealer inventory, now rare), aftermarket, or used parts.
Price Variation
The same part for the same vehicle may have dramatically different prices across channels. Example (illustrative) for a brake pad set for a common sedan:
- Dealership OEM: $120
- Online OEM (discount): $85
- OES (supplier brand): $65
- Premium aftermarket: $50
- Economy aftermarket: $30
- Remanufactured: $25
- Used (from salvage): $15
Quality, warranty, and fit differ. A neutral description reports the range but does not declare one option "best."
Consulting Observation
When describing the auto parts market, a consultant notes:
- The ratio of OEM to aftermarket parts sales (varies by country and regulation)
- Average part prices by category
- Fill rates and delivery times for major channels
- The impact of vehicle complexity on parts availability (new cars have more proprietary electronic parts)
- The role of insurance companies in directing parts choices
The parts market is larger than many realize. Over a vehicle's lifetime, parts and repair spending often exceeds the original purchase price of the vehicle.
