I was just reading a thread about relocating a battery to the boot and I had a thought.
If you have your battery in the boot, does it have to be a sealed/maintenace free battery so you don't get the hydrogen fumes venting into the cabin?

 

If it's not a sealed battery the battery box must be sealed and vented to the atmosphere.
You can get a sealed battery and install it in your boot w/o box.

 

I'd better get that done then, my Skyline came with a non sealed battery, I wonder how that passed our 6 monthly warrant of fitness inspections.