Being a taxi driver always ranks among the most challenging jobs in the country, so the guys head to Las Vegas on a quest to create the ultimate taxi, aiming to keep both driver and passengers happy. After getting some experience riding along with real cabbies, they reveal their creations, put them through a series of tests and then hit the Vegas strip to see who can get the most tips. Then we review the newest supercar to come out of the UK–the McLaren MP4-12C, and see how it stacks up against a good old American NASCAR Cup car.