I'd doubt you'd need an RS4 MAF - my throttle body and inlet trunking are about the same diameter as the Mersey Tunnel!
And the RS4 uses a totally different engine management system to the R32 - it has TWO ECUs with a direct bridge - though the actual signal from the MAF should be the same.
I'll dig the p/n for you - but it may be superceeded, as I havn't updated my ETKA for about a decade!
(I'll come back and edit this post after ETKA boots . . . . de-dum, de-dum, de-dum)
OK, the actual sensor isn't listed separately - you have to get the MAF housing too - 077 133 471 M.
