Trying to figure this all out (aftermarket stereo system)

That coustic amp is very good quality. It was top tier back in the 90's and is still a decent amp. I would chuck the cd changer, they never worked very good even when they were new. Dont fool yourself, that is a horrible installation and wiring job. I would yank it all out and start from scratch. Those amps need air flow across them, wont last long covered up like that.
So looks like there are two coustic amps, a crossover(white box) and an EQ.
Im curious, just how many ground wires can you put on a trunk latch?