I'm considering changing to these tips...

http://cgi.ebay.com/ebaymotors/PONTIAC-G...emZ280121041937

or maybe these...

http://cgi.ebay.com/ebaymotors/FORD-EXPL...emZ280120463459

I was even considering if I went with the 12in models about just leaving the muffs in the rear off since I have the Hushpower in place of the factory resonator. However I do like the angle cut of the first ones and the double wall design.