NFS M3 with an actual BMW v8 sound
bmw_m5_b from ProStreet, with the A variant also available (bmw_m5_a = stock/bmw_m5_b = engine upgrades installed). Works as you would expect. Just drop the 4 .gin files into the game files and run the modscript. To change to the A variant, simply replace the "b" with "a" under engineaudio in pvehicle (don't forget to do it on both M3 GTRs listed, I don't know why there's 2 because I literally installed MW a day ago but just in case).
There is a demo video in the comments, for the people who haven't played ProStreet or heard an IRL E90/E92 M3.