Originally Posted by BMW786
So would modifying the suspension with run-flat tires affect the ride that badly? I don't have the Sports package on my 325. I am new to all this modification stuff btw.
H&R race springs are VERY stiff for a street-driven car. Then factor in the 18" wheels & runflats, with their very stiff sidewalls, and you wind up with a car that's far more suited for track duty than street duty. The runflats are just one contributor to this situation.