Watch Scrapheap Challenge online: Episode 8 Spy Cars

The Challenge Spy Cars The last quarter-final mission, should our challengers choose to accept it, is to build a stealthy 'spy car' for use on a secretive information-gathering exercise. Their reconnaissance vehicle will have to carry the entire team both under and over obstacles which are just two feet from the floor, turn on a sixpence and then back out of trouble. They must avoid detection whilst infiltrating a sinister-looking base protected by guard posts, razor wire, security cameras, alarms and laser beams. Once inside, they must limbo, hurdle, twist and turn their way into (and out of) danger in order to steal a top-secret briefcase before making good their escape. Bakewell Puddings The last time we saw the Bakewell Puddings, they were pitting their wits against Rough Riders, three North Sea gas engineers from Hull, in Off Road Rescue. Nick Marriott, Mark Elliott (Smell) and his nephew Andrew Charlesworth (Charlie) are from Bakewell in Derbyshire. All are into bikes and racing (Motor Cross and Enduro). Mark and Nick have been friends for 20 years and have been in the same Motor Cross team as well as in a punk band together. Mark started to teach Charlie to ride at the age of nine, so it's fair to say bikes are this team's thing. Mark is an engineer, Nick is an architect and Andrew is a Rolls Royce engine inspector. These guys are also outdoorsy, sporty, rugby-loving, mountain-climbing kind of people who participate in the annual Bakewell raft race and the odd cross-town wheelbarrow race. They thrive on a challenge and have plenty of ingenuity and humour to keep us all entertained! John Ricketts (also known as Johnny Nitro) is a drag racer of the classical style à la American Graffiti. He owns, maintains and races his 8-litre 1965 Chevy and has been known to fit a nitrous oxide system to a Ford Anglia. When he's not being a petrolhead, John can be found catching tubes (that's surfing to you and me) off the Cornish coast. Up 'n Atoms Up 'n Atoms reached the quarter finals by bowling over the REME Rebels, three female soldiers from the Royal Electrical and Mechanical Engineers, in Bowling Bangers. Ali Day, David McFarlane and Jimmy Ridewood are expats living the life of Riley in Geneva. They work at CERN (Europe's largest centre for nuclear research) and explain their work as Star Trek-type stuff, experimenting with smashing particles together to see what happens. They're science boffins but not in the slightest bit geeky. They enjoy playing on the slopes of Switzerland, rugby, British sports cars and a good pint or 14. They have a background in off-shore work and have nuclear power station training – so there is an extremely solid engineering skills base here. They claim that James is the 'looks' of the team, Ali is the 'brawn' and David is the 'brains'. Up 'n Atoms' expert is Jim Chalmers, a creator of whacky vehicles. By day he runs a large workshop outside London but he's happiest when he's inventing – most recently he patented what could be the world's smallest commercial hovercraft. He's recently got in trouble with the police for strapping a jet engine to the top of an Escort. Future projects include building a McLaren F1 – for the road! The judge John Hetherington is a veteran of Scrapheap after judging the Minesweeper challenge back in series 4. John is a professor of engineering design at Cranfield University and head of the Engineering Systems Department at the Royal Military College of Science – he's the man who teaches potential Qs!

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