Originally Posted by dbworld4k
I experienced very similar issues once with my E46. Turned out to be blown RTABs, and that solved it. In your case, assuming the RTAB replacements were good quality and installed properly and the alignment was done properly, the next thing I would check are your tires. How old are they, and how's the tread? Have you had your rims balanced recently to check for bends/warping?
Worst case, bring it to a good independent shop (one of the sponsors on this forum) and have them take a look at it. I'd recommend Stance Factory as they're suspension specialists and should definitely help.
I got OEM RTAB's and got it installed at a reputable mechanic, not a sponsor, but a good BMW mechanic. Maybe I should get the alignment checked again. Any recommendations for alignment shops?
My summer tires were new Hankook v12's bought last summer and balanced at Simplytire and the winters are Pirelli Sottozero's about 3 years old now. The rear end behaves the same with both tires so I was thinking it wasn't the tires?