It's not the run flats. I switched to regular performance tires (due to cost not performance) and I still hit hard. I have to baby it over speed bumps.
I actually have a loaner 328i now (NO SPORT PACKAGE) and I can hit speed bumps at 25MPH no problem. It obviously has run flats.
Who ever says its the run flats.....not sure what their smokin.
)))
Sports package == fun == rough ride!! But it's worth it.