LAS VEGAS – It was a quick visit when Nate Shelton attended his first SEMA show in 1972, at the time held in the Anaheim, CA, convention center.

He twice walked the floor of the modest auto aftermarket expo, then drove home in time for lunch. “It takes a lot longer to see the whole show today,” Shelton, now SEMA chairman, tells WardsAuto.

The trade group began 50 years ago as the Speed Equipment Manufacturing Assn. Keeping its acronym but changing its name, it became the Specialty Equipment Market Assn.

Its annual event has grown into an extravaganza that fills every hall of this city’s sprawling convention center.

The 4-day show draws more than 130,000 attendees and features rows of performance, accessory and customization products from nearly 2,500 exhibitors. Their displays fill about 1-million sq.-ft. (92,903 sq.-m) of floor space.

That’s just indoors. The convention center’s vast parking lot is filled with assorted special vehicles, both old and new, including uniquely customized models.

SEMA began as a representative of independent businesses, many of them small enterprises putting out single products. But automakers and major suppliers have become a show presence, using the event to introduce specialty parts and vehicles. The automotive aftermarket is a $31 billion industry in the U.S.

Chevrolet blitzes the show with 39 vehicles, including performance and special-edition versions of the all-new Corvette Stingray, Camaro, Silverado pickup and Sonic compact.

NASCAR’s Jeff Gordon is on hand to introduce his satin-finish Gordon SS concept Chevy. At a press conference, he’s introduced as a top racer “and a great dealer.” He owns Jeff Gordon Chevrolet in North Carolina.

Chevrolet also introduces a new line of factory-engineered performance parts and accessories, pitched as preserving the vehicle warranty when a Chevy dealer installs them.

SEMA touts its annual event as “where the newest and most innovative products are seen first," says Chris J. Kersting, SEMA president and CEO.

The trade group bestows various awards at a breakfast gathering in a hotel ballroom “that’s about the size of the first SEMA show I went to,” Shelton says.

Automakers winning SEMA’s “hottest” vehicle awards are: the Jeep Wrangler SUV, Ford F-Series truck, Ford Mustang sports car and Scion FR-S sport compact.

Product winners include Viking Performance’s Berserker active shock management system. It provides advanced ride and handling and makes up to 1,000 shock-absorber adjustments per second. It’s a system first developed for military combat vehicles.

Another SEMA product award winner is Coker’s modern tire with a retro whitewall appearance. “It looks like a classic, but drives like a radial,” says Corky Coker, head of the namesake tire company.

Not open to the public, the SEMA show attracts car devotees of the first degree. Among them is Kyle Hall, marketing coordinator for Theory, a communications and design firm in Charlotte, NC.

“I grew up with gasoline and oil running through my veins,” he says, showing no harmful effects from those metaphorical body fluids in his system.

Another car-buff attendee is Jamie Meyer, GM’s performance marketing manager. “Personalization and customization is a big piece of business for our company,” Meyer tells WardsAuto.

Who buys souped-up and dressed-up cars instead of basic vehicles that get owners from point A to B?

“Marketing folks and SEMA itself spend a lot of money to study and classify that,” Meyer says. “Certainly, it is someone very passionate about cars, and who wants a vehicle that feels special when they drive it, and makes them feel special driving it.”

He grew up in a family of car enthusiasts. His grandfather sponsored a local dirt-track stock-car race team. “My dad had a 1955 Chevy and my mom was something of a hot-rodder who drove me to school in her big-block Chevy Monte Carlo.”

Meyer still owns the ’86 Mustang GT his parents gave him when he graduated from high school in upstate New York 26 years ago. He is quick to add: “I have a Corvette Grand Sport in my garage and drive a Chevrolet SUV every day.”