Originally Posted by kirungi okwogera
As someone who has done a little sound work for film and TV I can say it is entirely possible and likely that they are not "lying", and recorded the real cars inside and out and ended up with weak results - keep in mind the system must match the RPM, clutch, shifting, turbo noises to what you're actually doing in the game, so it is playing (ideally) a different sound file for every little gradation of RPM. This is very hard to switch between smoothly and sound responsive and correct. The easier way is to create loops and change the frequency (pitch up or down) instead of using a different loop for the many many steps between idle and redline RPM. The problem with this way is even if you started with a real sound, it ends up sounding synthesized because the computer is changing the frequency rather than using different sounds for each step of RPM. Perhaps that's it?
The other issue is reverberation simulation changing depending on if there's a rock wall on one side or the other, or both, or forest vs. open space, narrow village street, etc. I haven't heard enough of WRC3 to criticise that aspect, but Dirt 3 did both pretty well.