I have a battery box as per the spec below mounted behind my seat roughly in the normal position. It states wet cell batteries, however there a sealed spill proof wet cell batteries available. Do you think one of these would pass tech?

4.8.8 Batteries All wet cell batteries must be located outside of the driver or passenger compartments and must be securely mounted. Dry Cell or LiPo battery packs may be located in passenger compartment area providing they are encased in a sealed box that is securely mounted to the vehicle and is vented externally of the vehicle. Box must be made of a minimum 3mm aluminium (or other material of equal or greater strength) and may have a panel or lid fitted for access providing the lid or panel has an air-tight seal and is securely fastened to the box

Well.....I ended up fitting an Odyssey PC925 which works extremely well. 380 CCA turns it over very nicely with the hi-torque starter.

I ran a 12cell Ballistic Lithium Battery in my car.... 500CCA which was mind blowing!