I used a MARINE "thru hull" to run the + battery "thru" the floor. That way you can disconnect the thing from the underside of the car without ripping out the back seat etc.
I had to make a "patch" because the previous "builder" (a f'n joke) had three holes drilled in this area - and just ran the + AND - cable thru the floor -- sharp edges and all.... and had these two giant cables all the way forward. It was obvious they didn't understand electricity!
I ran out of RED shrink tube in this size - thus it's black - which is a no no - but ASSume anyone getting this far into the car - will be able to see what was done. The underside of the car IS RED shrink! I use black welding cable for it's oil and grease resistance -- and it's super fine copper strands.
