Mercedes gets a facelift to compete with two other roadstersWith its iconic logo on proud display, the SLK is focusing on luxury, with plenty of room in its sumptuous interior. But will the new styling actually leave the competition behind? Two other cars, the BMW Z4 and the Audi TT 2.0 TFSI are close rivals. The BMW has a classic roadster look with its massive hood and rear-wheel drive. The Audi TT has an irresistible sound. Which of these three roadsters will take the prize?