Doc Hudson is a famous racecar, the Fabulous Hudson Hornet in Cars. After a big crash, Doc became the mayor, judge, and doctor of Radiator Springs. To date, he hasn't appeared in any System sets, but he appeared in the DUPLO set, 5815 Flo's V-8 Café.
Doc Hudson, also known as the Hudson Hornet, was an old race car who lived at Radiator Springs. He didn't like Lightning McQueen at first, but later got to like him. He ended up as Lightning McQueen's crew chief in the Piston Cup Champion tie-breaker race.