Why Choose Aftermarket Auto Body Parts?
There's a bit of controversy over what is best for your vehicle: OEM (original equipment manufacturer) or aftermarket?
A Short History of the Aftermarket
Henry Ford's idea was to have absolute control over every aspect of the manufacture of his Model T. Therefore, every component of that vehicle right down to the last carriage bolt was fabricated right there at the Ford plant in Dearborn. Now, auto owners have been modifying their cars for better performance since the beginning, but until the 1980s, they would have to have parts custom made to order or fabricate them on their own but if they were to attempt to market these performance parts to the general public, they would have soon received a “nastygram” from Ford's legal department ordering them to cease and desist or else.
Ultimately, as the dozens of car manufacturers that once existed in the U.S. swallowed one another up until there were only three, a problem became apparent: if your auto plant manufactured its own magnetos or widgets and that part of your factor got shut down for some reason, it meant that your whole assembly line came to a grinding halt. Originally, this was one big reason for outsourcing the manufacture of certain components: to insure that such components would always be available from one source or another.
This opened the door for many other entrepreneurs who found they could make a component of better quality for less, or offer “performance” parts that would allow any shade tree mechanic to do what performance enthusiasts with machinist's skills had been doing for decades.
Are They Always Better and Cheaper?
Not always. Aftermarket replacements for stock body panels can often be an ill fit, according to some body and fender repair people. On the other hand, there are many aftermarket auto body parts that look and fit just as good as their OEM equivalents and are usually much easier on your wallet. Some excellent examples are a front headlight assembly, side view mirror replacements, fog lights and rear tail lights. These parts can usually be bought from online auto body parts retailers for a fraction of the OEM retail price. These parts are also easy to install by the backyard mechanic.
Incidentally, such “aftermarket” equipment is used as OEM equipment by car manufacturers, for the reasons outlined above; therefore, it's entirely possible that your vehicle had Bosch components installed when you drove it off the lot. However, car manufacturers may use parts from any number of other sources as well which is why two cars of the same make and model can differ in terms of mechanical reliability.
The Performance Difference
One difference between OEM and many types of aftermarket equipment is performance. A car manufacturer has no way of knowing where a vehicle will ultimately be sold and what equipment will be street legal in a given state. Therefore, stock vehicles are designed to be “middling” in terms of performance as well as appearance. If you want high-performance components, such as a high-flow muffler or a cold air intake or would simply like to add sporty accents such as fender flares or a spoiler you'll have to turn to the aftermarket. This also applies to safety equipment such as cross-drilled or vented brake shoes and high-intensity headlights.
Be sure to take a look through the ABPA, Auto Body Parts Association website.