Dr Don Tarr was born in Napa, California, but was raised in Africa before returning to the United States to attend medical school. When he was offered an internship in Miami, Florida, and decided to settled there once qualified.
He started racing at the Hialeah Speedway where he became friend with Bobby Allison. He graduated NASCAR Grand National Division in 1967 driving the Tom Raley Ford in the Dixie 500 in Atlanta finishing 36th after blowing a head gasket on lap 47. His best finish for the year came in the Old Dominion 500 at Martinsville finishing 16th after an electrical failure on lap 404.
In 1968, he drove his own Chevrolet in 12 of the season’s 49 events. Despite a number mechanical failures and crashes, Tarr managed to finish 14th in the Dixie 500 at Atlanta and the Rebel 400 at Darlington.
In 1969 he drove his own car as well as Ray Fox’s Dodge. In Fox’s car, he finished 9th in the National 500 at Charlotte, 8th in the Firecracker 400 at Daytona, and 6th in the World 600 at Charlotte. Tarr even led six laps in the inaugural event at the Talladega Speedway before engine failed.
He would later tell how he “drove like an idiot” using 22 tires in 129 laps and lapping as many cars as he could. For his efforts at, Biscayne Dodge of Daytona Beach presented Tarr with a street version of the Dodge Daytona that he had driven.
In 1970, Tarr competed in 17 races, finishing 10th in the Atlanta 500, and 7th in the Rebel 400 at Darlington and the Tidewater 300 at Atlanta. He came sixth in the Firecracker 400 at Daytona driving one of the famous winged Plymouth Super Birds.
He only entered 4 races in 1971 with a best finish of 7th in the Talladega 500. After losing his Coca-Cola sponsorship, Tarr retired from the sport.