Honestly this has got to be one of my favorite little features of the S550!
2015 Ford Mustang GT, EcoBoost Models Pack 3 Steering Modes, 4 Drive Modes - Torque News

I think that is absolutely stellar! However I'm not sure if the modes fiddle with suspension settings as well...Those models were equipped with the 3 mode driver selectable steering system as well as the 4 mode drive mode settings with steering options included Comfort, Normal and Sport while the 4 drive modes will be Snow/Wet, Normal, Sport and Track.
These different steering and drive modes seem to be fully independent so a driver of the 2015 Mustang GT or EcoBoost could pick the Track drive mode and Comfort steering – provided that is what they like the most.
2015 Ford Mustang GT, EcoBoost Models Pack 3 Steering Modes, 4 Drive Modes - Torque News