I have had one on all my Challengers, I feel for the price it is a great product to have to help prevent build up. You'll see a lot of different opinions, but the pictures were all the proof I needed.
Speedlogix is the leader in aftermarket performance parts and accessories for modern Mopar vehicles including the Dodge Challenger, Dodge Charger, Dodge Magnum, Chrysler 300, Ram Trucks, Jeep Grand Cherokee and Wrangler. Officially Licensed by Mopar.
www.speedlogixstore.com
American Brothers makes a cool one too that can be paint matched and engraved: