I have a g35 coupe that I just put a computer in. It should be pretty much the same for the sedan. I just ran an 8 gauge power line from the battery to the computer in the trunk. Its pretty easy, the only hard part is getting through the firewall. Theres instructions on how to do this on g35driver.com here:
One note about these instructions is that they say you need to cut the grommet to get the wires through, This is NOT true, dont cut the rubber, just take the tape off surrounding it and slip the wire through with a hanger, this is what I did and it works great just remember to retape it up.
If you want to see how I did the rest of my computer and xenarc screen, check out these threads:
How-To on how I mounted the screen:
The rest of the computer can be found here:
Originally Posted by cwho122