Jay Leno suffered serious burns to his face Sunday when a car in his garage suddenly caught fire, according to a report. The former “Tonight Show” host is being treated at the Grossman Burn Center following the incident in Los Angeles that injured the left side of his face, TMZ reported Monday. Leno, who was born in Westchester, reportedly avoided injuries to his left eye and ear when the car unexpectedly exploded. A representative for Leno didn’t immediately respond to a Daily News request for comment. Leno, 72, canceled a scheduled appearance Sunday at a financial conference in Las Vegas, ac…