I was in the process of installing a sub, amp, and new head unit. Already replaced door speakers. Luckily I noticed an issue before I really got started. There are 2 wire harnesses plugged in to the factory head unit. One is the basic port for your radio and the other is for the amp that powers the door speakers through the stock radio. I don't want to bypass the amp, I want to integrate it into the new head unit. I know it's possible but I can't seem to find anything online to give me information on it. I don't know if I'd be ordering the right part or how to install it. I'm sure it comes with instructions, but I like to prepare so I don't come across any surprises... like this one. Any help or suggestions?