Showing yet another year of strong growth, the specialty-equipment aftermarket parts business grew by 9 percent in 2005 to end up at $34.3B. That's nearly double the size of the market ten years ago, and in each of those years, the auto aftermarket has grown at a faster rate than the US Gross Domestic Product.

As SEMA points out, the automotive aftermarket in the US now rivals book sales, the pet-care industry, and the coffee business, and is even larger than the global athletic-shoe market. Yeah, sure, everyone needs Starbucks and comfy shoes, but apparently there's just as much demand for mobile audio, nitrous systems, and big wheels.

[Source: SEMA]