Best of Top Gear, The Challenges! With Jeremy Clarkson, Richard Hammond and James May. This special compilation of the best ever challenges sees the boys go '70s retro in £10,000 Supercars, Jeremy takes on a tank in a Range Rover Sport, Richard tries to out-sprint a champion greyhound in the new Mazda MX5, James 'Captain Slow' May goes all extreme and takes on a BMX biker around Lisbon in the new Renault Clio, and we find out what's the best convertible for wig wearers.