2004 545 manual transmission. at around 70 mph, I get a vibration from the rear of the vehicle. not violent , but kind of like a butt massage. shifter and passenger seat shake a little. I've been through rims,hub rings, tires, balancing, etc. everything looks good and tight as far as suspension, but the vibration is still there. anyone have this and get it corrected? I'm thinking of a lot of different things as to what it can be but don't want to just go and replace part after part. thanks

Check the prop/drive shaft. Maybe a weight came off. Otherwise you might want to try a different tire shop.

A worn rear shock could be to blame it could be the rear wheel bouncing up and down that you can feel.

More info may help.. What kind of rims? OEM or replica or aftermarket..? What balancing machine was used to balance..Etc

Thanks for the replies folks. They are 18" TSW wheels in a staggered set up. The old wheels had cracks and bends and were the result (I think) of the vibration originally. New rims and tires and vibration was better. Vibration came back a few months later and one of the rears had a bubble. Replaced tire and all was well until recently. I was thinking that one of the rear shocks might be worn causing the wheel to hop. I actually replaced the driveshaft a year ago and it didn't help. The hub rings are plastic and correctly sized.

Check the play on the rear wishbone or dog bone mount? Older cars had these issues. Have you ever swapped your rims back to stock and did the same issue occur?

Think I found it. Let me know what you folks think. Crawled under and checked the rear bushing that supports the differential. It rubber has separated from the metal and has som play in it.

check those upper arms too

Its either #14 guiding, 19 wishbones or 2 balljoint


http://realoem.com/bmw/diagrams/r/j/178.png

I also noticed that the rubber boots on the wishbones are torn, they're tight, but leaking grease.