Plot: This week, The Grand Tour arrives in Stuttgart, the home of Porsche and Mercedes-Benz. In this show, James May takes the new Honda NSX supercar to the Eboladrome to push its cutting-edge hybrid technology to the limit and Richard Hammond immerses himself in the world of doomsday preppers as he constructs a ‘bugout’ vehicle that will allow him to survive a bleak future of nuclear winters, alien invasions and massed herds of zombies