Yesterday, the entire day, the front end was shimmying as if each of the front wheels was 1/2 out of balance. Today, solid as a rock. WTF gives with these cars? I was ecstatic yesterday because I thought the loaner would be the perfect guinea pig for the dealer to diagnose. It's their car, they can have it as long as they need it, etc. Now I'm no better off than I was before. Two cars that shimmy intermittently, and rarely when the dealer has them. Great. BMWNA? Help?