[Snax]

Looks like a bit of both to me. Most of the dust difference is at the rear above and aft of the wheel, though there is some difference ahead of them as well. The rear bumper and hatch showed no difference I could see from side to side.

Above the rear, a clear line of dust can be seen with heavier dusting on the uncovered side. Everything else ahead of that is less obvious. In comparing these with discs only on the front, the dusting above the rear for the uncovered wheel looks about the same vs. totally uncovered IMHO.