Well, I'm not the same guy who posted up there, but I do have the same question, and I can tell you what my car is... !
I have a 2001 PT Cruiser, and I want to run an auxiliary input wire from my factory stereo for my ipod. I guess the newer models have the aux input right in the front, but the 2001 doesn't. I see I can buy this (
http://www.discountcarstereo.com/detail.aspx?ID=360) but I'm not completely sure it's the right part, and I'd like to look behind the stereo just to see what kind of connections I have.
While I'm on the topic, doesn't $65-100 seem kind of steep for an adaptor for an 1/8-inch stereo phone plug? I'm paying only $12 for the equivalent thing for my Mercedes! Isn't there a better way (without going the FM broadcast or cassette adaptor route)?