I've just recently purchased an 06 Crossfire roadster. Been reading this thread and decided to go out and find the capacitors suggested here. Went to a car audio shop and they had some nice caps called Bass Blockers. Real nice with insulated wires and available in a few different sizes. Here's a link with a wiring diagram:
All About Bass Blockers I went with the 300's. I'll be installing them this weekend. Wish me luck!