Tinkering at photography myself, I watched Tim Wallace training sessions on KeblyTraining.com. I can't say I've a lot of people to compare his work with but from what I have seen, he's the best in the business.
He uses softboxes mostly. And battery strobes. He's an absolute artist. I don't think his site explains how he does it and you probably don't want to spring for the Kelby class but you should take a look at his site:
Tim Wallace: Car Photographer and Commercial Automotive Advertising Photography