For Charles, automobile racing was a way to clear his head from the pressures of business. His racing career spanned nearly 20 years, during which he drove against the best in the sport in IMSA (International Motor Sport Association) events and raced as a team with his son, Rob, on the NASCAR circuit. In his later racing years, Charles was also an investor in the Pirelli Racing Series, in which he and Rob drove Porsches and Ferraris. By the time he hung up his helmet, he had amassed 19 wins, including in such classic races as the 12 Hours of Sebring and the 24 Hours of Daytona.