Hi, Im thinking of fitting an amp to my 172 and was thinking of doing it myself, question is does the standard head unit have RCAs out? Or do I need to use the speaker out wires? Also, what would be the best way to route my speaker/power/remote/RCA if my amp is mounted on the back of the back seat? Oh, and does the standard fronts and tweeters have crossovers? Any advise would be great, thanks!