I replaced my 205/55 GSC's with 215/50 KDW's. Only thing to be aware of is wheel well clearance varies considerably from car to car. My E0's original left rear tire rubbed the wheel well liner straight from the factory. I replaced the liner with the updated one when I switched to the KDW's. However, if you don't have clearance/rubbing problems with the 205's, chances are you won't with the 215's.
