20 inch rims thats a little hard to get good handling out of that.
If that were the case then I doubt the SVT Performance package for the 2011 Shelby would include 20"rear wheels AND deliver better handling. It really depends on how the suspension is setup to handle the wheels, and if the car has the power to move them. A set of light 20" wheels can be more benficial than a standard set of 18 or 19s
2005 GT Premium - Mineral Grey 5-speed MT
Vortech Supercharged - Steeda Billet LCAs, Steeda UCA, UPR adj. Panhard bar, FRPP K-member brace, GT500 Strut Tower Brace, Walbro 255lph Dual pump, FRPP 39# injectors, AIS Water/Meth Injection, Ported Throttle Body. 440rwhp / 406rwtq