Largely retired, although he still owns a trailer shipping, distribution and haulage business called KKW Trucking in California, where he continues to live. Firestone bought the business when he was just twenty-two back in 1967. He established his business, growing it before taking up his hobby of racing cars. Dennis is also involved in the tyre industry. After a broken neck sustained in a crash ended his career, Dennis stopped racing but still keep links with the sport though, and still races in historic events. Dennis was also a regular Super Vee and USAC Gold Crown driver in his career.

Biography last updated 10 Jul 2016