GTR 2 Sound modding help?

'Kay, new member here.
I have a question, basically I love how accurately the M3 GTR's soundwork all in all is but I feel the gearbox noise is kinda muddy, it's satisfactorily captured, but could be even better.
Then, I figured that because there's a tool to extract sounds from NFSMW 2005, I should try and port the M3 GTR gearbox sound from it to GTR2 to replace the stock one.
So, in Audacity, I opened the files from NFSMW 2005, changed their properties to match ones in GTR2, saved changes and replaced the files.
Now, the actual problem I need help with. I tested my mod ingame, the gearbox noise isn't heard at all..what did I do wrong?
Thanks in advance and apologies if this is a total n00b question.