IDK what the pioneer harness looks like, but I didn't need anything special to install my JVC unit. I unplugged the Kenwood and the harness in there plugged right into my JVC. I was pretty surprised. All you should need is a harness from BestBuy. Just go there, get one for the Protege, and don't open it until you know you actually need it (after you pull out the stock Kenwood and see if the harness in there will plug into your unit).