I downloaded a bunch of music videos from Limewire and plan on burning them to a DVD for playing on the DVD player in my car, so others can watch them while i am driving and listen to the music

I have 30 .MPG files, all have 44100khz (whatever the standard is) for audio and encoded them to a DVD
I used AUTOMATIC for everything under the VIDEO SETTINGS, and everything came out fine, EXCEPT

When playing them in my car the audio for some of them sounds awful, some sound OK, and some sound great
Granted the sources for the videos are all different, but they have all made it into the .mpg format and have the same audio quality when I scanned the file and all sound great on my computer.

Could anyone help me out here and possibly explain this?

Thanks

Have you tried using other programs (like divx to dvd) to see if it just the programs fault or the dvds player