well i just recieved my new radio from crutchfield and decided to call the techs in advance to talk me through it. turns out its quite simple for what i want. im using the factory amp but not the cd changer. who the hell buys cd's any more? the metra 70-8112 pligs in to the harness you remove from the amp ( it was the furthest one to the right on my 1996 lx 450. from there you have to extend 2 blues (which hook together) and to the blue from my radio, the red, yellow and black. i have 4 rca cables.( just purchased the extension and 4 (barrel connectors) to extend these to the rca plugins to the back of the radio. so (acording to the crutchfield tech) you now receive power from the amp harness plug, or something like that. now i do notice the orange illumination wire is not included in the harness from the new amp harness but there is an orange wire in some of the origional radio wiring plugs( i think it the gray one if i remember correctly) i think i can just tap into that orange wire to get dimm function. not 100% sure.