Modern cars with EBD use the rear brakes more around town and before coming to a stop to increase refinement and reduce nose-dive.

I've seen several reports now of seemingly faster rear brake wear (usually RWD) from various makes, i suspect the cars are driven quite vigorously and the aforesaid stability conrtol whatever its called is applying the brakes as necessary to maintain composure.

Paul it might be an interesting experiment to turn the stability and/or traction control off, if you can, for a week and see if the brake dust is still the same.

I know nothing about Quattro but i wonder if the back brakes are larger than the normal car, where most car's rear pads are half or less the area of the fronts, maybe that yours is Quattro could be something to do with what you are seeing.

Wonder also if it could be how the car's brakes are cooled, maybe the fronts are designed for passing air to blow through them for cooling, scattering the dust away from the wheels maybe a useful side effect?, the rears due to where they are might not have this designed in cooling.

Only surmising here, haven't the foggiest really, interesting to find out why though.

Well thats interesting, but how nice that someone out there actually enjoys being in control of their own car and can feel the difference their input makes.

Thanks for the update.