Right Is is easy to retro fit a 21st century head unit, ie AlpineINE W9900BT or similar and keep existing steering controls? Will I lose any OEM functionality? The bonus of this is I can finally make use of that camera in my rear bumper. I do have BOSE amp / speakers, is it difficult to wire them up also? Pending on what feedback I get I just might remove the old relic. * I know I need a fascia, I see these ones.