Jeremy Clarkson travels to deepest Gloucestershire to take part in a group car test with a difference - driving amphibious vehicles into a lake. Featured models include the Dutton Marinerand a replica of the Lamborghini Countach. Quentin Wilson considers the pros and cons of buying a used VW Golf VR6, tipped to be one of the year's most popular second-hand performance cars. Wilson praises the model but advises that it may be difficult to find. And Michele Newman compares the latest small sports coupes from Honda and Toyota that have been aimed with the youth market very much in mind.