Originally Posted by VIP1

You can retain the stock steering wheel controls with an aftermarket headunit by using an adapter. There are a few different models depending on the brand of headunit you buy.

If the headunit supports a wired remote (port on back of headunit), you can get the wired version of the PAC SWI-?. (I put a ? there because there are different models for different headunits units)

Here are the ones I found on Crutchfield:
PAC SWI-ALP - Alp/JVC/Ken/Blau
PAC SWI-ECL - Eclipse
PAC SWI-PS - Pioneer and Sony

Otherwise, you can use a PAC SWI-X which is the universal IR version that works with most headunits that have use an IR remote.

I have a Pioneer AVIC-D3 headunit and use a PAC SWI-PS to retain the steering wheel controls.

Originally Posted by Whtdragn101

Thought I would add that the new Alpine models use the SWI-JACK. Certain Clarion, JVC, and Kenwood hu's use it also. It works AWESOME with my cda-105, and the steering wheel controls actually do more with the aftermarket hu then the factory one.