I have a Kenwood amp from another vehicle that I want to put in my Tacoma. I have the non-JBL stock 6 disc changer head unit and plan to keep it for a while until I eventually do the full stereo upgrade. My Kenwood amp has speaker level inputs and I am wondering about where to tie into my front speaker wires. I have read that it should be after any factory amps and am not sure if my stock setup has an amp or not (guessing that it does). Also, I am planning on getting a set of Polk Audio db6501s for the front door, anyone have these or heard anything?