Rear cargo area dimensions?

[Pendulum]

I need to know the amount of space between the back seats and the hatch, can anyone help?
I need the following dimensions-
Side to side floor space
Floor to top of seat, NOT INCLUDING HEADREST
back of seat to rear hatch

I've got a Fit coming in for an install and am trying to determine if I'm gonna need to build a custom box, or if I can use the one I have here.
Thanks.

[Vtecracer]

Go to dealership with tape measure. thats what i would do

[Pendulum]

...
If that was an option I wouldn't have posted, but thanks.
:)