Well, you can't have everything, so if you want fast+removable top, you are limited to just a few cars and from mitsu you have the 2 spyders....
basically when you have a modified top of a car you lose alot of the good features of the car.
in this top gear video
http://video.google.com/videoplay?do...588&q=top+gear
they compare 3 convertibles(TT, 350Z, xfire)....as it turns out there was no definate winner because all 3 of those cars were designed to be hard topped sports cars....and with cutting the evolved to be convertibles...
in the end they suggested that if you are going to get a convertible, get one that was designed to be a convertable from the ground up, like the S2000
anyways watch the video, its good....as a matter of fact, you should go to video.google.com and search for "top gear" its an excellent series you can all watch for free, I watched all of them, totally worth my time, and probably worth yours
(warning: prepare to dedicate a whole afternoon+evening if you want to watch all of them)