Re: Running amp through back speakers
Better off with a new head unit... But if you are dead set on not getting one, you have to use a line-out converter (LOC). You crimp the LOC onto the speaker wires. It shouldn't affect the sound you hear coming from the rear speakers, either.
CDT carbon fiber 6.5" mids & DD T2 tweeters on a Polk Audio PA D4000.4
Tantric HDD12 in 3 cubes/6x17" aero on a DC 5.0k
2 runs Monster Cable 1/0, SounDrive rca's, Singer 310a 6 phase, Exide G78 agm's, plenty of deadener