Car: 2004 Audi S4 So I recently hit a median with my front passenger wheel, which bent my lower right control arm pretty dang far back. After replacing that control arm. Took the car to the shop and had the alignment done. No reports of any problems while doing the alignment. Alignment came back great. After leaving the shop i noticed a vibration in the front passenger side wheel. The faster I was going, the greater the vibration. Thought it was bad tread wear. After that I swapped to my summer wheels/tires. Same problem with the vibration on these wheels too. So I jacked up the car, put it in neutral and started spinning the wheel. I noticed that the wheel wobbled up and down constantly. Went to check the wheel balance. It was fine. Swapped the back wheel up front and tried spinning it again. Still the same wobble. At this point I noticed that the rotor itself was wobbling up and down also. But the brake caliper stayed put. Took the car to the shop, they said they checked all control arms and ball joints. Nothing wrong with them at all. How can that be possible? Anyone have any idea of what needs replacement? Someone said they think it might be a damaged/bent knuckle. Any ideas? Thanks!