Run the 4 ga kit from the front battery to the trunk, within the first 18 inches there needs to be a fuse and fuse holder. More than likely the kit came with a 150 amp fuse and holder. After the fuse, run the rest of the wire to the trunk. There you attach your distro block and you put the 4 ga going to the sub amp and the 8 ga to the comp amp. The runs of wire from the distro should be pretty short.