On July 18, during the summer off-weekend, Earnhardt crashed a Chevrolet Corvette C5-R during a practice for the American Le Mans Series Grand Prix of Sonoma at Infineon Raceway. The car slid off course and hit a concrete barrier during warm-up the day of the race, rupturing a fuel line and causing the car to burst into flames with him still inside. He suffered second and third degree burns on his neck, chin, and legs partially due to not wearing a protective balaclava with his helmet. The burns prevented him from finishing two races where he was relieved by Martin Truex Jr. (at New Hampshire) and his DEI teammate John Andretti (at Pocono) in the middle of the races. In the fall, Earnhardt became the first driver to sweep a weekend at Bristol by winning both the Busch and Nextel Cup races in the same weekend.