Not to worry. I replaced the fronts at 58k miles, with FAG bearings. Appears I need to do it again at 85k. Louder that crazy. I did check all wheels for looseness, and that is NOT an issue, just the rumbling.

BTW, the Quattro rear bearings are the same PN, so if you buy an extra, it will fit on any corner....

There isn't any choice anymore since hub+bearing assembly has been discontinued (one exception - febest assembly on amazon but it doesn't seem to be of good quality so its out). What I did was to also order used OEM hub+bearing assemblies from eb and I plan to install these first and take my time to remove bad bearings and press in new F.A.G.s. for later use. I had started a new thread for help with this repair and steveracer has been very helpful!

Changed both bearings finally! Had to soak in penetrating oil (several hours) and chisel the housing off the vertical. Rest all went smooth. Right bearing had the play and some metal bits coming off, left had no play but wasn't smooth when I tried to rotate it. Unfortunately, although it makes significantly less noise now, there still is noise coming from some other part of the drive train (?) at the front end. Mostly between 40-60MPH and pretty annoying around 60MPH. At 80+ there is little vibration as well. What else should I look into and replace next? Will try to record the noise over the weekend and post it.