If im using a line output converter will i need to mess with the radio or head unit at all?

im wiring the LOC to the rear speakers so i can hook up subs and amp|||No, the only wires you'll need to grab are the rear speaker wires. If you can catch them in the rear, then do so. The only downfall is if you plan on adding an aftermarket radio in the future. Then you'll have to run your RCA's all over again.