I just installed a metra 99 7625B dash kit in my 09 g37 I put my apple car play head unit from my old car in it. don’t xav150. my car comes stock with bose sound system and amp somewhere in the car. (don’t know where it’s located) to use that amp in the car I had to plug in 4 different rcas a purple grey black and white one into my 4/6 rca ports. they were the rca to each speaker in the car. (back left, back right, front left, front right) there’s 2 ports left a yellow port for camera and a black port. how can I install 2 more rcas for my 2 12 inch kickers ?