The team drive the Aston Martin Rapide, the Porsche Panamera Turbo and the Maserati Quattroporte as they try to find the world's greatest four-seat supercar. Richard test drives the the Chevrolet Camaro SS and the Mercedes E63 AMG. Rupert Grint and Rubens Barrichello take their turns as the Stars In A Reasonably Priced Car this week,