A note for those who hear crackles in Grand Prix 3/4 with a Creative Sound Blaster X-Fi card:
I have tested the following X-Fi drivers with both games and noticed the following:
5.12.2.1143 (2005)
-Both games should work perfectly with these drivers.
5.12.6.1187 (2006)
-You may experience crackling sounds.
-> Switch from "Entertainment Mode" to "Game Mode" from X-Fi Control Panel and it should work.
If there are other ways to get GP3/4 working correctly with X-Fi + newer drivers with Entertainment Mode, updates are welcome and I'll be thankful.
If there are newer versions of X-Fi drivers which works perfectly with GP3/4, updates are also welcome.