I'm interested in this thread because frankly, I'm not impressed with the X1 sport-line ride quality and am fairly sure it's because of the 18" RFTs (my X1 has Continental RFTs). I think the ride is harsh and bouncy and generally sucks for a vehicle in this price range. Now, my E90 had the same tire but on 17" rims and I thought the ride was pretty decent, but, I think the 3-series suspension has a few refinements that the X1 or 1-series vehicles don't (can anyone confirm that?). So, I'm debating either getting 18" non-RFTs installed on my sport wheels and, or just say the hell with it and get some non-RFTs and some 17" wheels and be done with it (but still have the sport seats
. Any/all opinions welcome, these wheel/tire experiments can get expensive!