S15, E7: Jeremy Clarkson, Richard Hammond and James May compare the Mercedes SLS, the Porsche 911 GT3 RS and the Ferrari 458 Italia in an epic road trip up America's east coast. Along the way they undertake a series of challenges culminating in a fight to find the fastest way into New York, all in the name of crowning the world's greatest sports car. Plus, another celebrity takes to the track as The Star in a Reasonably Priced Car.