Thanks for the reply's, i am putting 2 12" subs in the boot area with 2 1000w amps. one for the subs the other for 2 sets of component speakers front and back. the sub amp has 3 x 40amp fuses the other 2 x 40amp fuses the manual says add amounts together and add 50% so 120 +80 = 200 + 50% (100) = 300 amps..I know about the little fuse box near the battery but i have not seen that type of fuse up to 300 amps and my 0 awg cable is too big for it.so i want to mount a fuse holder near too the battery. worst place or my only option will be under the battery tray.