Noobie here: I'm attempting to install an amp and sub in my 99 E300 and have come to a bit of a jam in regards to three items-1. where to pass the power cable (8ga) from the battery (under the rear passenger seat) into the trunk and 2. where to tap for the remote power switch for the amp (i was thinking the cd changer, which I have removed, but the wires are still there?!?, but am unsure of the wire to tap into). My third question stems from tapping into the rear speakers which are able to be manipulated from the trunk to splice with a LOC converter-again colors? and has anyone run into any problems this way?

Any suggestions and advice would be much appreciated. IF you have any pics that would be even better.
Thanks