Because I can! Lol no, I brought them up to specify the inner joints because almost everyone ignores the inners.

 

I have exactly the same problem as TheJazz7. There appear to be plenty of other A8s with the same issue. Worn CV joints appears to be the consensus cause. I'm going have mine changed with genuine parts and I'll let you know if it works. Its definitely not tyres, transmission or wheel alignment. I've had the bushes checked, too. The vibration is strong enough at 75mph for front passengers to notice.

 

Lubing the sliders and pads/rattle clips is a very important step in servicing brakes. If you just did an A8 upgrade and forgot to clean and lube everything, then the caliper sometimes hangs and causes this vibration similar to bad wheel balance.

 

Wow, I had totally forgotten about this thread! Apparently my "comment notifications" weren't set. Got no love at first, and then everyone chimed in :-)

Good point regarding lubricating the brake components. Since i cleaned the **** out of them prior to painting, and I did lubricate the slider pins, pads, etc., I'm very hopeful that is NOT the case.

One other wrinkle to add. I hear a noise at low-speed, kind of clicking, coming from that rear-passenger area. Doesn't sound totally metal-on-metal, but it's certainly audible. Speed variable...above 10mph it happens so fast it just blurs together. I had initally thought I picked up a nail in a tire or something...I'd have to double-check the CV joint info, is that clicking a symptom of a bad component?

Either way...sounds like my CV-Joints need some love. I'll get to that AFTER I get my damn window motors/regulators fixed, AND swap in new ABS module. All before the snow flies, hopefully!