As well, does anyone know where an ISO plug can be purchased?
Looks to me like it's included in
this kit (the smaller plug), but I'm not 100% sure.
From what I hear on other boards, the sales people a
Crutchfield are very good - try giving them a call (1-888-955-6000) I couldn't find the plug on their web site, but they might still have it...
Edit: Hmmm, if you meant the ISO plug that goes on the harness - that is one half (upper) of the larger plug in the first link, while the lower part, IIRC, is normally the speaker outputs (on an Aktiv system it might be the leads to the stock amps)
I believe that kit + a harness adaptor for your car (car brand plug to wires) is all you need to hook up the harness and into your car.
/Michael