Dog box in Mazda 6 (2014)

Hello, at the moment I drive a Passat B6, which should by now be renewed so slowly at 12 years. Since I had a 626 station wagon before and my brother is satisfied with his CX5, I did a test drive yesterday with a Mazda 6 (2,2L diesel with 175hp, full cabin). I was actually very satisfied, even if he can not keep up with the passat from the space, but the driving fun was a lot higher. But the question, I get because my dog box in there? Maybe one of them has one, give me a few measurements, because on the internet I find nothing suitable. The basic shape of the box is 80x68cm, that should fit, but in height I already make my first thoughts, the box is 67cm high and has on 67cm still 50cm deep. Now I do not know how much space is with closed tailgate, between the rear seats and the rear flap (if you take out the boot cover). he could say at what height the back seats end up and if my box fits in at all. To simplify it, I drew something quickly, even if I’m not an artist, I hope you know what I mean.