That's what people like me are probably afraid of I would imagine. Don't post much really as I'm more of a reader/learner from these forums so my post count or longevity wouldn't help. I also don't buy too much from online sellers on forums. Sucks that these dbags screw it up for everyone...
Have a Pioneer head unit. Used the PAC-RC with the 2 wpt-440 pig tails that were mentioned in previous posts. Soldered all connections except for the power and ground for the PAC which I picked up off of the original radio harness near the head unit (used taps - tight space...fat fingers...
Need a tuner to do it (sct, etc). You may not have to though if you're keeping the overall tire size the same (lower profile tire on the wheel). What is your tire now/what are you putting on?