I finally got it working with a constant bitrate mp3. But it doesn't seem to work with any of my .wav or vbr .mp3 files. Is the reving car sound supposed to be there as a defulat or something?
Nope, most likely the "car sound" is produced by mp3 sound driver on your system due to some error. It works with *all* mp3 files on our test systems, so it looks to be your-PC-related issue, however I'll ask our developers to check this once more.