I have the Magnaflow Cat-back system. It runs around $ 500 shipped. Unless you have your own tubing bender and can TIG weld you would have difficulty duplicating it yourself for less. Quality stainless exhaust systems are not cheap but I wouldn't put anything less on a quality German performance/sports car (which, aside from the Chrysler badges, is what a Crossfire is...) The Magnaflow is a cinch to install and uses two mufflers with nice big built-in tips. You can cut off the rear cats and make it a true dual system later on if you want to. Once my warranty expires that's my plan!

Slim