I went the industrial route for all my power wiring under the hood. I used Phoenix contact blocks that are DIN rail mounted and can be bridged or isolated to fit your needs. It allowed me to run 1 wire from the battery to the contact block through a fuse, then hook each relay off a terminal on the assembled block. Each terminal on the block can source up to 60 amps each at 12VDC. I will take pics soon as I have time to get out there and pull the battery; I hid the block in front of the battery at the back of the core support. That's what happens when you used to work around high powered industrial controls for a living like me.