Thanks for the reply bigaudio.
My head unit harness does not have a blue wire for the antenna, nor did it have a wire for the amp power control.
As for bridging the channels on the amp, the instructions specifically state and show that I have to use a Y-splitter.
http://vault.alpine-usa.com/products...PDX-5%20OM.PDF
The part that I am confused on is running the wires from the amp to the cross-overs. Do I run a connection from the + of channel 1 and a connection from the - of channel 2 to the left cross-over? Then repeat for channels 3 & 4 to the right cross-over?