Help! Metra 70-5521 Amp Harness Install

[cbird1177711]

Thanls in advance for any help, really. So, I am installing a system In an 08 gt mustang with the shaker 1000 system. I am taking out the rear subs and replacing them with a new amp and sub, but I would like to keep the front door subs functional. I have the metra 70-5521 harness and a 12v to 5v regulator to prevent the popping sound when it turns on (i have since seen people using resistors but since we no longet have a radio shack, i dont feel like waiting for one to get here, and im pretty sure wal mart or lowes doesnt carry them and theis will work just as well). I am pretty sure I know how it works but would like some confirmation before I solder.* (See first pic) Do I connect both of the blue wires to the red wire on the regulator, and then ground the black wire on the regulator? My main question is where exactly do I connect the yellow and red wires on the output side to? The blue wire from my new head unit? It is labeled auto antenna electric wire. And iv already soldered the blue to blue from the main part of the harness, should I un do thay and solder in the voltage regulator output to the blue wire, leaving the blue wire from the main part of the harness unused? (See second pic) And just so im clear, the red and yellow are soldered together and then soldered to the blue antenna wire? After that I should be done, just hooking the rcas into the front RCA output? Also iv seen that people usually just use the white rca, not both, is this necessary? Thanks for any help at all guys - Cbird.

 

[cbird1177711]

Sorry, this was supposed to be the second pic.. and for some reason it keep uploading upside down, you get the point though... are both the red and yellow wires from the output side of the regulator supposed to be soldered into the single blue wire (auto antenna) from the head unit's wire harness, leaving the blue wire from the main part if the harness unused? Thanks!