Flowmaster Sounds from 7 different mufflers
Version 1
http://www.youtube.com/watch?v=YlGqSd7QjWQ
Muffler Shootout 2
Version 2
http://www.youtube.com/watch?v=EUUteVjNdI0

Dynamax Sound Cart
http://www.youtube.com/watch?v=Z26anAVEQsk

Magnaflow Demo
http://www.youtube.com/watch?v=sEsfeSvinaI