I recently got a factory 91-92 radio from a friend but I think I am going to need the external amp to run it correctly. So I need the amp and preferably the wiring. Also, if you could tell me where and how I need to run the wiring that would be a definite plus. I really don't even wanna think of how much one of these would cost from Toyota. Please respond ASAP as I am really tired of my circa 1987 tape deck and would like to get some CD sound in there.