Background: Marion Lee "Mickey" Thompson (December 7, 1928 - March 16, 1988) was an American auto racing builder and promoter. A hot rodder since his youth, Thompson increasingly pursued land speed records in his late 20s and early 30s. He achieved international fame in 1960 when he became the first American to break the 400 mph barrier, driving his Challenger 1 to a one-way top speed of 406.60 mph at the Bonneville Salt Flats and surpassing John Cobb's one-way world record mark of 402 mph. Thompson then turned to racing, winning many track and dragster championships.
Context: Thompson was born in Alhambra, California. In his early twenties, he worked as a pressman for the Los Angeles Times while pursuing a lifelong love of hot rodding. He later became involved in the new sport of drag racing. Tireless and innovative, he found success as a championship driver and instinctive automotive technician.  Over the course of his career, Thompson set more speed and endurance records than any other man in automotive history. He is credited with designing and building the first slingshot dragster, in 1954, moving the seat behind the rear axle to improve traction when existing racing tires proved unable to handle the output of increasingly powerful custom engines. This car, the Panorama City Special, debuted at the first NHRA U.S. Nationals at the Great Bend Municipal Airport in Great Bend, Kansas in 1955. The car ultimately ran a best speed of 151.26 mph (243.43 km/h). A change so momentous would not happen again until Don Garlits introduced the rear-engined digger in 1971. Thompson also was noted for being the first manager of Lions Drag Strip in Wilmington, California, in 1955.  Thompson collaborated with Fritz Voight on a 1958 twin-engined dragster. This car achieved a best speed of 294.117 mph (473.335 km/h). It provided lessons later applied to Challenger I. Determined to set a new land speed record, Thompson achieved fame when he drove his four-engined Challenger 1 at better than 400 mph (640 km/h) in 1960 at the Bonneville Salt Flats, becoming the first American to break that barrier.
Question: What was he most successful race?. Whats the answer?