Meanwhile, Hammond sees if the Aston Martin V8 Vantage Roadster can win a straight half-mile drag race against a German on roller skates with a 300 horsepower turbo powered rocket backpack, Clarkson braces himself with extra safety precautions on the track as he climbs in to the Caparo T1, and Simon Cowell returns to see how fast he can be when he has a go in the Lacetti.