Ant Anstead goes behind the scenes with the car hunters of auction house RM Sotheby's as they travel the globe tracking down expensive classic cars for auction. These rare models - from Ferrari to Aston Martin, Lamborghini to Jaguar - come with mind-blowing price tags, sometimes in excess of $10 million. These are the best and most valuable collector automobiles on the planet: cars that are rare, limited editions or race winners, and often with fascinating histories or famous owners. But will the super-wealthy turn up to bid? Can these classics hit their multi-million pound estimates or will they fail to reach their reserve price?