i think Jordo's jumping the gun a little bit. I dont usualy drive my X through mountains, i did for the first time this past weekend. i could feel a wobble reaching the top of a hill at 80mph, it'd start, i'd let up off the gas, it would go away and i could continue on my way. the wierd thing is it was totally random. going on flat ground i have never experienced it. my buddy who has a 740il had a wobble at higher speeds and it ended up being his drive shaft. i know our drive shafts are shorter so i dunno if that is a common wobble that can be caused by a bad drive shaft. i wonder if the guibo disc can cause a wobble like this. X5turtle, the sensation was like an imbalanced wheel right? and it would go away when you let off the gas?