if your planning on passing the pits with a battery in the back, pits want fully sealed box with a pipe going to the outside of the car etc etc blah blah expensive excercise, even if its drycell, they dont care
otherwise, its quite simple and a good idea for weight distribution and also to extend battery life due to less heat, if u get a yellow, return it back to standard, its alot easier to do that, than make the pits happy
funny enough, i got an engineer to approve of the battery in boot install, gave a cert for it, but pit inspector still didnt like it for alot of stupid reasons, i gave up, not worth the hassle from cops / pits etc