Aftermarket parts must meet federal standards.
The U.S. regulates most custom car parts, also called aftermarket parts, and has regulations requiring certain characteristics, but federal agencies rarely enforce these regulations themselves. This is in large part due to the size of the aftermarket parts industry.
Fun Fact
In 2009, the aftermarket parts industry transacted about $38.9 billion and employed about 322,000, according to IBIS World. Most of these parts are sold through some roughly 40,000 retail chain establishments.
Laws
The federal government regulates the custom parts industry through the National Highway Traffic Safety Administration (NHTSA), according to the Specialty Equipment Market Association (SEMA). The NHTSA only issues regulations for aftermarket parts that would be required on a new car.
Features
All NHTSA regulations go into the federal register, according to SEMA. The NHTSA, however, relies on manufacturers to enforce regulations within the industry -- taking action only when it suspects a manufacturer's product violates NHTSA regulations. In instances where manufacturers have trouble interpreting NHTSA guidelines, it sometimes issues clarification letters on its website.
