Before you start editing Registry files or ripping audio, try the most common community-driven fix. A fan-made DLL file has effectively solved this for 90% of users.
The silence in Need for Speed: Most Wanted is deafening. The game loses 50% of its personality without Styles of Beyond kicking in just as you smash through a donut shop roadblock.
In the early 2000s, many gamers played their racing games by inserting the game disc while a separate audio CD was in their second disc drive. NFS MW adapted this by using a "Mixed Mode CD" structure. The game logic tells Windows: "Play Track 2 from the CD-ROM drive."
(most common fix on modern PCs)
