Don Flynn played a crucial role in two of the great growth-company stories of the past 40 years. As chief financial officer at Waste Management, he brought high finance to the lowly world of trash, raising vast sums so the company could acquire hundreds of little haulers and dominate its industry. And Flynn was one of the three original investors who bought Blockbuster and gobbled up the video-rental industry before brilliantly selling the company to Viacom in the mid-1990s.

In both of those cases, however, Flynn, a burly former high school and college football player—he played tackle on both offense and defense—wasn't the quarterback. Wayne Huizenga at Blockbuster and Dean Buntrock at Waste Management were the play callers, the CEOs.

After reaping a sizable fortune from the Blockbuster sale, Flynn could have called it quits and spent his days relaxing at his 19,000-square-foot home on the water in Hillsboro, Florida (for sale now for $35.5 million), and scuba diving around the world off his 171-foot yacht, the Battered Bull. But, Buntrock recalls, Flynn had the urge to build another big company, using the Waste Management–Blockbuster playbook. "He wanted to try these things on his own," says Buntrock. Yes, the entrepreneurial imperative.

Flynn settled on the auto-dismantling business, an industry with 6,000 mostly mom-and-pop players. This time, Buntrock and Huizenga were investors in Flynn's venture, which he called LKQ. With Joe Holsten, a former Waste Management executive, as CEO, LKQ quickly bought up small dismantlers and came to dominate its industry.

Flynn died October 10, at 72, after a period of failing health. But the company he leaves behind, with $2.5 billion in sales and a market capitalization of more than $4 billion (after an initial public offering in 2003), has plenty of room to grow. The Chicago-based LKQ buys about 200,000 of the 11 million or so cars junked in the U.S. each year, cutting off the parts and selling them to the nation's 44,000 body shops and 76,000 auto-repair shops. It also makes aftermarket parts. LKQ's commitment to technology—this in an industry in which well-managed databases are hardly the rule, though there is no more crucial question than, "Do you have the part?"—has given it a vast edge in productivity.

Flynn's son, Kevin, remembers one of his father's lessons about being competitive. They were golfing together when Kevin was 13. Kevin needed his father to miss a 6-foot putt to claim $24 in wagers. Kevin was already counting his winnings. "He knocked it in and turned to me, and all he said was, 'You lose,' " Kevin recalls. "To learn from my dad, you had to watch."

Flynn's taste for risk wasn't limited to business. At least nine knee operations, a result of football, made walking difficult for him in his later years. So he scuba dived. Flynn would fly to Tahiti and meet up with the Battered Bull and its crew. "He was into advanced adventure shark diving—without the cage," Kevin says. And liking things big, Flynn also sought out whale sharks, which don't bite but thrilled him nonetheless, Kevin says: "They're the size of a school bus."