Hi all, for one I'm new to the site, and two, I have an 05 Limited with the factory installed JBL system in it...which is only ok at best. I wanted to know if the factory deck has the capability of adding an external amp to it, or if not how do I do it? I took two 8" bass tubes outta my truck and my Rockford p400.2 out as well and would like to put them in the runner. Thanks!