When I was looking at cars I knew I wanted a convertible. While the cost and performance of the Corvette was interesting, you see a boat-load of Corvettes on the road and I wanted something a little different. It finally came down to a choice between the Lexus SC430 (great company/smooth quiet reliable car and also a hard-top convertable) vs. the SLK 55 AMG. If I had chosen using my head, I would have gone with the Lexus. The SLK had the performance and looks, but questionable reliability. My heart won the battle. So far I have not been disappointed.
#1 - The Engine!!! I let a friend drive it the other day, and he said "I have not felt acceleration like that since the last time I took off in an F- 16. #2 - The hard top convertible. Very nice!
Backing up into a parking spot is a challenge as low as you sit in the car and due to the door height. Mirrors that automatically tilted down would be nice.