S20, E4: Jeremy Clarkson, Richard Hammond and James May bring relief to flood-stricken areas of Britain by building a car that can turn into a hovercraft. After a bumpy start, the presenters demonstrate the brilliance of their creation with an eventful journey down the River Avon. Also in this show, Jeremy is on the track in the insane Mercedes SLS Black and the 739 horsepower SLS Electric, while Hollywood star Hugh Jackman is the star in the Reasonably Priced Car.