London and many other European cities face the prospect of a 300 million penalty every year over bad air. Engineers say part of the solution lies with electric transport, so this week the Naked Scientists are getting under the hoods of a new generation of vehicles ranging from the first electric buses to tomorrow's supercars. Plus, news about how scientists are making objects levitate in the lab - with sound - and why there are now 3 types of "type 2" diabetes...