And reverse flow as well.
The initial reason I went with the RS4 MAF was that I have a bosch car. I ended up buying a 4.2 a6 airbox (RS4 MAF fits right in it, looks factory) and RS4 MAF. A known transfer sheet makes me happy.
Even though the MAF fits and the bottom half of the airbox is completely identical to the B5 ones, the top half is longer and has a different angle, I assume they had to compensate for engine bay size differences.
Left one is an RS4 airbox, right one is the one that ddillenger has, so unfortunately this only works for A6 people.