The SLK was the benchmark car for origami roof action, and many others have followed in its wake. An all-seasons convertible that dramatically loses its roof at the touch of a button, the latest SLK is much better than the first incarnation. Thousands have been sold - and not just for the badge, for this has evolved into a real driver's car. The ride is firm, but the seats are comfortable and the driving position is excellent. Roof down, not a strand of your hair will move, and the whole car is beautifully solid. Competitors worth checking include the superb Porsche Boxster and the BMW Z4.