I'm ordering my stereo stuff off ebay in a couple days and getting some friends to help me put it in. Anyways, what all will I need to put it in besides an amplifier wiring kit. How many harnesses will I need? It's going in a 89. I'm putting in a HU, 2 12s, amp, and new 4x6s and 6x9s.

 

You are going to need the harness that connects the factory wiring harness to the aftermarket HU wire harness (roughly $15), i believe you also need the antennae adapter (roughly $10), and about 5 feet of 12 gauge speaker wire to wire the subs. You will also need another converter if you are replacing a bose stereo.