What is The Automotive Aftermarket? How Many Car Enthusiasts Are There?
Author: Jon Hedges
Jon has 40 years of marketing experience in the automotive aftermarket industry.
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Hedges & Company answers important questions about the automotive aftermarket in this article.
Let’s start by defining the automotive aftermarket:
Automotive aftermarket definition:
The automotive aftermarket is the industry offering products, services and innovations for vehicles, after they leave the factory.
Auto aftermarket and GDP
The aftermarket includes replacement parts to keep a vehicle functioning, up to vehicle customization and personalization. The aftermarket is huge, supporting millions of consumers. In fact, the automotive aftermarket is so large, it represented 1.9% of US Gross Domestic Product (GDP) in 20241.
How many jobs are available in the aftermarket
The US automotive aftermarket supports 5 million jobs. A Hedges & Company analysis shows those jobs support 242.3 million licensed drivers driving nearly 290 million registered vehicles in the US in 2025.
Those 5 million jobs are at repair shops, collision repair services, tire shops, manufacturing companies, parts stores, installation centers, performance shops, and wholesale distributors, to mention just a few. These jobs might help maintain or improving a vehicle’s functionality, or customizing its appearance.
How many car enthusiasts are there in the US?
The automotive aftermarket supports nearly 26 million automotive do-it-yourselfers (DIYers) and enthusiasts in the US in 20252. That means auto enthusiasts make up 9.6% of the 2025 US population over 18 years old3.
Enthusiasts searching on Google
Automotive enthusiasts and DIYers do 104,000,000 Google searches each day!
The calculations for all these statistics is shown at the bottom of this page.
But what really makes the automotive aftermarket different from other industries? This article digs into the unique characteristics that define the automotive parts, accessories and service industry and its economic, technical, and cultural significance.
We’ll show you specific things that define what the automotive aftermarket is, and what makes the automotive aftermarket unique among industries in the world.
5 things that make the automotive aftermarket unique
The automotive aftermarket is like no other industry on Earth. Other than the fact that our industry obviously sells goods and services for vehicles, there are five main things that stand out as unique.
1. Automotive aftermarket products have complex fitment requirements
The automotive parts world is full of products that have specific fitment and compatibility requirements. Fitment is very important. In fact, if you try to install an incorrect part it may result in mechanical failure. A part for a ’57 Chevy has no place on a 2025 Bronco. Well, maybe a generic trim-to-fit floor mat would, but not much else.
The aftermarket’s fitment requirements even spurred the development of the ACES data standard for fitment (Aftermarket Catalog Exchange Standard) in the early 2000s. The ACES standard covers over 60,000 combinations of year, make and model. But fitment can include other things, like bed length, four wheel drive vs. front wheel drive, pickup truck cab size, and many other requirements.
Few industries require anything close to this level of fitment precision for products.
2. The automotive aftermarket has a wide product range
The automotive aftermarket includes many millions of part numbers. About ten years ago, we came up with an estimate of six million part numbers. Today, with more imported parts, more private label parts, more “manupactured” parts, more complex technology used on vehicles, and due to parts proliferation, it’s probably more than twice that amount today. Not many industries have 12 to 15 million part numbers to keep track of.
Not only do millions of new vehicles each year add to the growing list of part numbers, but vehicle age is a factor. For one thing, the average age of a vehicle on the road keeps getting older. For another, vintage and classic cars are a big deal in our industry. There’s still demand for parts that fit a Model T Ford, and some Model Ts are over 100 years old.
3. The aftermarket requires complex technical knowledge and specifications
The automotive aftermarket is full of technical requirements and specifications. The Society of Automotive Engineers (SAE) defines thousands of standards for vehicle components, and has been doing so for over 100 years. SAE has defined standards for just about anything you can think of that goes on or in a vehicle. They have nearly 50,000 technical publications available for download. These cover a broad range of things, from designing snowmobile headlamps, to testing the upper temperature limit of elastomers used in cars.
That technical requirement carries over to professionals in the automotive aftermarket. Engineers and mechanics undergo rigorous training and testing in order to perform some types of work. The National Institute for Automotive Service Excellence (ASE) is a non-profit organization conducting testing for automotive technicians. There are currently over 222,000 technicians holding some type of ASE certification, with an additional 68,000 students holding ASE Entry-Level certification.
4. The aftermarket embraces DIY car culture and customization
We love our cars! The Do-It-Yourself (DIY) culture is live and well, and was recently fueled by the COVID-19 pandemic, that created an uptick in DIY activity. The aftermarket is supported by millions of automotive enthusiasts to love to tinker and fix things.
Supporting the DIY culture are thousands of car clubs, websites, car shows and cruise-ins, and even books and movies.
Related to the DIY culture is the desire for customization. Enthusiasts like to personalize their vehicles to make them unique. This can take the form of custom paint, custom interiors, aftermarket tires/wheels, vehicle modifications to suspension or drivetrain, and many other things.
Just like the fashion industry, trends go in and out of style in the aftermarket. Last year’s rat rod may be this year’s restomod.
5. Tremendous economic impact of the automotive aftermarket
As we said at the beginning of this article, the automotive aftermarket is 1.9% of US Gross Domestic Product (GDP) in 20241. By 2026 there will be over 300,000 businesses in the US serving the auto care industry in some way, including any stores that sell parts, car washes, tire dealers and convenience stores. That doesn’t count 130,000 new and used car dealers, adding up to over 430,000 consumer-facing businesses by 2026.
Add in distributors, wholesalers and manufacturers and it’s well over 540 million businesses either directly in the automotive aftermarket industry, or supporting it.
All those businesses employ people, and the Auto Care Association has employment in the auto care industry at 4.8 million people. That’s a lot of folks paying taxes, supporting families and contributing to local economies. So, what is “aftermarket?” It’s a whole lot of businesses and people contributing to the economy!
Speaking of huge, the automotive aftermarket supports a massive trade show each year in Las Vegas. The SEMA Show and AAPEX are the 4th largest trade show in the US, and one of the largest in the world.
Challenges and trends in the automotive aftermarket
The aftermarket faces its own unique challenges, unlike any other industry. Here are three examples.
1. The aftermarket has continuous technological advancements
1. The aftermarket has continuous technological advancementsThe automotive industry constantly improves its technology (one reason the average age of cars is increasing). The aftermarket has to keep up with that new technology in order to supply products and services. Many times the aftermarket industry develops its own technology that ends up being used by OEM manufacturers.
The auto industry and the automotive aftermarket contribute to developments in electric power technology, artificial intelligence research, predictive maintenance, cybersecurity, innovations in manufacturing including 3D printing, recycling technology, emissions and environmental technology and too many more to list.
2. Regulatory compliance for automotive aftermarket products
Please don’t “roll coal.” Photo courtesy EPA.
The automotive aftermarket has to comply with complex regulations around emissions and safety. These regulations can be at the Federal, state or local level.
The Department of Transportation (DOT) regulates vehicle safety and under the DOT umbrella are departments like the Federal Motor Carrier Safety Administration (FMCSA) and Federal Highway Administration (FHWA).
If any original equipment manufacturer (OEM) parts governed by regulations have to be replaced, the aftermarket parts replacing them also have to be tested and comply with regulations.
Emissions is a big area of regulation. The California Air Resources Board (CARB) and the Environmental Protection Agency (EPA) regulate any part or function that creates emissions. OEMs and their suppliers have to comply with these regulations, as does any replacement aftermarket part that affects emissions.
3. The aftermarket’s seasonal trends
The aftermarket has unique seasonality. Many industries have regular peak seasons but not the aftermarket. Many products have peak sales in March, April and May. Some products related to travel in cars, cruising, or general maintenance will peak in the summer. Many truck products related to hunting, fishing, camping or tailgating will peak in the fall. Towing products will sell well in the weeks leading up to Memorial Day and Labor Day. Collision repair products will sell well in the winter and after an ice storm. Winterizing products, batteries, snow tires and wiper fluid sell in the winter.
Conclusion
The automotive aftermarket industry a huge, dynamic, evolving industry. It combines a huge economic impact with cultural impact and technology.
What do you think? Did we leave something out? Let us know!
Frequently asked questions
Q: What is the automotive aftermarket?
A: The automotive aftermarket is the industry offering products, services and even innovations for vehicles, after they leave the factory. The aftermarket includes replacement parts to keep a vehicle functioning, up to vehicle customization and personalization.
Q: How big is the automotive aftermarket?
A: The automotive aftermarket industry represents 1.9% of US Gross Domestic Product (GDP). By 2026 there will be over 300,000 businesses in the US serving the aftermarket, including stores that sell parts, car washes, tire dealers and convenience stores. That doesn’t include 130,000 new and used car dealers, adding up to over 430,000 consumer-facing businesses by 2026.
Q: How many people are car enthusiasts?
A: There are nearly 26 million automotive do-it-yourselfers (DIYers) and enthusiasts in the US in 2025, or 9.6% of the 2025 US population over 18 years old.
Q: How much do auto enthusiasts spend on their hobby each year?
A: In the US auto enthusiasts spend approximately $3,193 per year on their hobby.
Q: What makes the automotive aftermarket unique?
A: The automotive aftermarket is unique because of complex parts fitment requirements, it has a wide product range with over 12 million part numbers, products have extensive technical requirements and specifications, it is supported by a DIY car culture and desire for customization, and the economic impact of the automotive aftermarket is larger than most other industries.
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Footnotes
1Calculation for the automotive aftermarket making up 1.9% of GDP is based on US Gross Domestic Product (GDP) at approximately $29 trillion in 2024, and the US light, medium and heavy-duty motor vehicle auto care industry at $545.9 billion (Auto Care Association/MEMA Aftermarket Suppliers Joint Channel Forecast Model published in the 2026 Factbook).
2Calculation based on Hearst 2022 Auto Enthusiast Study showing enthusiasts spend $2,846 per year, then adjusted for inflation to $3,193 in 2024 based on CPI; total auto care sales to DIY end users in 2024 in the Auto Care Association Channel Forecast Model of $81.5 billion. The calculation shows 25,534,500 automotive do-it-yourselfers and enthusiasts in the US in 2024. The resulting percentage of 9.6% of the US population over the age of 18 also aligns with previously reported percentages in recent years from SEMA and Auto Care Association.
3Calculation based on US Census Bureau estimate of population over 18 in 2024 at 266.9 million people and the above calculation showing 25,534,000 automotive do-it-yourselfers and enthusiasts in the US in 2024.
