mine is E53 3.0 sports with 19" tire/rim... I'm thinking of downsizing the tire/rim combo to 18" for the same reason mentioned above.... the regular road that I drove on is like driving on off-country road... and off-country roads are like "war zone"....
My kids tends to get car sick on regular roads on x5, but not on other suv/sedan we have.

ps.Omodos, do you experience noticeable improvement to ride quality (stiffness/comfort) when changed from 19" to 18"? Thanks in advance..