Big, bigger, biggest; Huge aftermarket numbers drive major automakers to the SEMA big top.(Specialty Equipment Market Association trade show)

Byline: BOB GRITZINGER

Consider the following numbers: 26 billion, 7400, 1300 and 12. Don't pain your brain trying to compute a connection: The numbers all relate to the Specialty Equipment Market Association aftermarket trade show, which began in 1967 in Los Angeles (back when it was the Speed Equipment show) and has been staged annually for the past 26 years in Las Vegas.

The first number relates to $26 billion in annual retail sales in the specialty automotive industry. There are 7400 booths occupied by exhibitors (there were 98 in 1967); and they're displaying 1300 accessorized and customized vehicles (vs. five in 1967). Finally, the even dozen is the number of major automakers who now consider SEMA a key stop on the annual automotive show schedule, up from just three original-equipment manufacturers that participated five years ago.

At the Nov. 5-8 show, their ranks include SEMA show lead manufacturer Chrysler along with Ford, General Motors, Honda, Hyundai, Kia, Mazda, Mitsubishi, Nissan, Panoz, Suzuki and Toyota. Most bring the usual customized versions of regular production cars, but some are also taking the opportunity to announce plans for future production models, though SEMA isn't open to the public at large.

In an especially odd twist, Toyota is touting tricked-out versions of its youth-oriented Scion vehicles that aren't even due in the market until next summer.

Like the rest of the automotive industry, SEMA is taking on a truck bent. Some of the biggest news comes from Dodge, with its new 5.7-liter Hemi, and from GM, with a string of high-performance production and concept trucks.

Since revealing its 345-hp Hemi powerplant in its heavy-duty trucks last February in Chicago, Chrysler has made no secret that engine production capacity far exceeds demand for the big rigs. At SEMA, Chrysler made the next piece of the plan official with the debut of the Hemi engine in its light-duty Dodge Ram 1500. The mid-2003-model-year truck arrives in showrooms in January, paving the way for the 2004 release of the rear-wheel-drive Hemi-powered 2005 Chrysler 300N sedan.