I think ppl have been purchasing third-party AUX connectors to connect the after market HU to the stock HU, otherwise its a full setup, amp, new speakers and so on.

Im assuming you will output the Alpine to the stock HU, thats why your asking about the AUX?

This product works for CL9, so I've read on their site http://www.pac-audio.com/products/pr...el%20Interface. Search for Alpine they have a few products.