Are you talking about in non sport mode? I dont feel a stiff ride in non sport mode, i think its a way a car should handle, hence BMW, mercedes. Lexus is you luxury soft ride car.
You can get a high profile tire - go to the 50 series - this will soften up your ride.
Better the suspension = less profile tire needed
Worse suspension ( like in the 60's) = more profile tire 70 series - helps to soften the ride and absorb crappy suspensions! but then again with 70 series you feel like you are on a cloud floating and no cornering ability!
2012 Charger R/T Road and Track w STP, SRT8 2012 wheels, Mopar CAI, Solo Performance high flow CATS, Solo CAT back, Billet Catchcan, Zoomers reso tips, Diablosport tune