In case you were not aware, the game comes with an improved (or butchered in case you don't like it) version of the soundtrack. The only way to play these songs is by having the CD in whenever you race/rumble. Not very convenient nowadays, right? Well thanks to users Massamo and adobekc19 that is no longer the case. They pointed us into the direction of an updated Music.pod file which emulates the full soundtrack. All you need to do is download and replace Music.pod and you will get to enjoy the full soundtrack.
Be sure to back up the original Music.pod in case you want to revert back to the non-CD audio version.
Where to get it?
Music.rar - unrar the file and you're set