Dart/Demon/Duster Exhaust Tips - help!

I have found that they do change the sound somewhat.
Maybe it's due to the fact that the exhaust exits straight out the back, but the rectangle shape does offer a better sound in my opinion.
They look good too.

I would definitely put them on your car, just don't buy generic look a likes that you find in chain auto parts stores.
They're really not that expensive for the right ones anyway.
JMHO,
Tom.