spots to mount a tank in a civic?

my trunk is 100% full (5000 watt system) and have been thinking about running bags instead of a static drop, but can't figure out where to mount a tank. those pancake tanks are too tall for my spare tire well, and the shortest normal tank i found was 8". I have 7" behind my back bumper but can't find a tank short enough to fit behind there I thought about behind the drivers seat on the floor since I hate people sitting behind me but how safe is that? I've seen how tanks look if and when they blow up and I don't want that happening right behind my back anyone know if any other ideas or even tanks that are only 7" tall?

behind the rear bumper just build a tank, or under the hood, there is room there, also there is room behind the front bumper too.  Dont forget room for compressors.

spare tire well if nothing in there or modify spare tire well to go deeper 

A side tilt-mount hydraulic pump is 6" tall - something to consider. 

No room for batteries for hydros, I have 3 extra batteries as it is.

I would like to stay away from dropping the spare tire well

never thought about up front. I eil have to do some measuring tomorrow

and I'm not sure who could make a tank or how hard it is

DO NOT put it inside the car!! I had mine blow up the the truck of my caprice a few weeks ago and it F***ED up all kinds of stuff! Luckily I wasnt in the car and nobody was in the back seat. Find a way to mount it outside behind the bumper or something. Good luck

What year civic? Hatchback, 4 door or 2 door? 

Will heat from the engine bay effect the tank at all?

did an accord afew years back used 4 one gal. tanks and wrapped the compressors around the side of the bumper basically ditched the reinforcement and absorber and just used the cover

Where can I get 1 gallon tanks from?? Or even 2 gallon tanks???