Ha ha. In the R33's there is a battery compartment on that shelf behind the back seat but it's not there in the R34, that's why 666DAN was able to put a sub there.
I've been a bit slack with mine but it is coming along. My box has been built but I haven't covered it yet or done any of my wiring.
And Wolverine, if you're reading this, I sppreciated your offer, I just bumped into someone with one and heard it then. Cheers mate.