The rear seats fold down, so there's actually plenty of room. I'm 6 foot 1 inch tall and was about 270 pounds at the time, and I would not have been able to sleep comfortably in the seat due to slouching over.
Probably only appropriate for favorable weather.
Edit: Incidentally, cars automatically turning off is a HUGE problem for K9 police units.
Overheating in cars is the leading cause of traumatic death for K9 units.
Police cars are heavily modified, but they are still based on consumer vehicle architecture, much like a shared code base.
Sounds like handler misconduct to me, but hey -- it's easier to blame the vehicle!
Too bad civillians don't have the same luxury of blaming the equipment.[0][1][2]
It's ridiculous -- and eye-opening -- that k9 units get that kind of treatment. I was always under the misconception (which is probably purposely portrayed in the media) that the dogs were treated as partners -- not tools. I guess that was too hopeful on my part.
[0]: https://www.boston.com/news/local-news/2017/10/16/owners-cha...
[1]: http://morgancountycitizen.com/2017/10/03/dog-left-in-car-di...
[2]: http://www.latimes.com/local/lanow/la-me-ln-woman-arrested-d...