The power of the new Porsche 911 Carrera S is put to the test on the track, Jeremy has to eat more than his words about the Vauxhall Astra and the Brits take on the Americans and Australians in a three car challenge.

We look at 4x4s to see which really can go off-road, but Jeremy takes it too literally and decides to drive a Land Rover Discovery up a Scottish mountain. Also, the Dodge Viper SRT-10 slithers around the Top Gear test track.