I picked up an excellent 2007 Z4 3.0si with the sports package, on eBay a few months ago - awesome car, heaps of fun. It has 80,000 miles on it, and looks and mostly drives like it's just off the showroom floor. But... it tramlines like crazy; especially when cold, the Michelin Pilot Sports have a mind of their own. After about 5 or 10 miles it seems to calm down - can't figure out if that's because the tires warm up, the electronic assist settles down, or my arm just gets stronger (actually, don't think it's my arm... I really do think it's worse at start-up). Is this a known issue? I'm going to take it in and have the tie rod ends looked at, but the tires appear evenly worn and are, I believe the factory size - 225 40-18s in the front and 255 35-18s in the rear, with lots of tread left, and are of matching brand and model.