Im planning on fitting a corsa brake servo and master cylinder to my nova, so my battery tray will be occupied, also for better weight distribution, I want to move the battery to the pass side corner behind the seat. Am I best to run a large copper wire to the front, or can I simply earth it to the shell in the back??? Also what does the MOT say about this, I assume I will need an enclosed battery box???
There should be no problem at all - Mini's have the very same arrangement. Earth'd at the back and wire runs the length of the car to the front for the starter (make sure this wire is well protected or runs inside). The box is a good idea but the battery will still have to besecurely fastened as it's not allowed to slide about. Box also stops unwanted contact with the posts.
Standard earthing strap bolted down to a clean bit of metal is fine, likewise standard battery cable for the 'to front' wire - have a look at the Demon tweeks racing catalogue for ideas of what's available and check out a couple of race cars/race websites for more info. Plenty of info out there!
Fasten battery box and lid down with strap - what type is down to you.