OAKBROOK TERRACE, Ill. | Industrialist Mike Yager, 57, prefers to be called "chief cheerleader." But his business sense is far from textbook.

Yager is CEO of Mid America Motorworks in Effingham, Ill., an aftermarket automotive components company that specializes in Chevrolet Corvette and classic air-cooled 1950-1959 Volkswagen Beetle, Karmann Ghia, Type 3 and VW Bus models.

In 1974, Yager borrowed $500 and began selling Corvette manuals, parts and other brand-related wares out of the trunk of a borrowed car.

Today, his venture has grown into a $40 million a year mail order and Internet catalog business to become the largest supplier of Corvette parts and accessories in the world, with a customer base of nearly 1 million Corvette enthusiasts.

Mid America Motorworks is also the nation's largest supplier of air-cooled VW aftermarket components. More than 5 million color catalogs are mailed out annually to VW and Corvette clientele.

"We've built our business one customer at a time," Yager said recently at a news conference with the Midwest Automotive Media Association.

According to Yager, the key to his success is built upon a simple principle: treat people fairly.

"Dealing honestly and personably with each customer as an individual, not only makes good business sense, but allows a greater sense of community and overall satisfaction with life," he said. "If we treat each customer right, we're going to make money."

Yager's words are backed by his actions as Mid America Motorworks throws "Funfest," a free on-site customer appreciation party.

Last year, Corvette Funfest drew more than 14,000 Corvettes and 45,000 people to the Illinois heartland to become the largest Corvette event in the world.

The 2006 Funfest for air-cooled Volkswagens drew an estimated 8,000 people and featured more than 1,200 vintage VWs on display.