David Kirby 
2008 BMW Z4 Hatchback 3.0si 2dr Hatchback (3.0L 6cyl 6M)
Perfect after changing tires
 WOW! I replaced the Bridgestons RF (run flat) tires, with Michelin Pilot Sport ASXL. The ride with the sports suspension, improved significantly, and eliminated the jolting, without compromising the handling. As a bonus, it may enable me to use the car year around in Upstate NY, without having to invest in snow tires, and if I can get even close to the projected 40K miles tread life, I will be even happier.