I just picked up an 06' 4.4i SP to replace the 04' that BMW repurchased.
The ride is excellent and a noticeable improvement over the ailing '04.
I'm on a road trip and I have noticed a vibration in the steering wheel and in the front seats while in the 60 to 75 mph range. The tricky part is that it is intermittent. Nothing bothers me more than taking a car in for service when the issue is on and off.
Any experiences would be appreciated.