Back story: Took a 4hr ride down to SW Indiana and I felt intermittent, strong vibration in my steering wheel at ~50mph. So I went to get the wheels rebalance and found out that my two front wheels had slight bends in them...Got them straightened and refinished at Wheels of America, mounted the tires, and rebalanced the wheels. I have Porsche Cayenne BBK, H&R 5mm spacers, B6 S4 Avus wheels, Tires are BN (<3k on them), replaced the control arms earlier in the year but I've haven't (never) replaced the wheel bearings (98k on the car).
Now: I still have intermittent vibration at highway speeds but it's not nearly as strong as once was...Is it the front wheels bearings? How do you know when you need to replace them? Could it be something else?
Any help would greatly be appreciated. Thanks guys.