I have a 2002 540i I purchased about 6 months ago and recently have experienced a "shimmer" in the front end when going between 65 and 75 mph. The car has 89k on the odometer and I thought the bushings might be issue. Last week I had new tires on the front, had new suspension arms w/ bushings replaced and an alignment done. Thought that might have solved the problem but still feel the shimmer? The rotors look good and don't appear to need replacing at this time. Any thoughts on what might be causing this and what I might want to check next?