I've seen those cage seperations.., you know, trap your dog in the rear hatch area.., by placing on these just behind the rear seat.., 

But what if you just attached a lease somewhere so the dog can't leave the hatch area.., what would be the best place to attach the leash in a carat??? I guess to a part of the rear seat, either a part of the seats frame or even that handle that pull on to make the rear seat come out to make a bed..., 

Of course if you park, you can open up the rear hatch (and if you have two heavy duty hatch struts it will actually stay open...,).., and then the dog can breath, the dog won't get too hot.., and no one is going to steal anything.., esp if the dog is big.., like a German Sheppard, or a Malulmut.., of course the Malumut might eat your rear seat..,