Take a look at the link in my signature, I have 2 German Shorthairs one is 58 the other is 70lbs. We had the divider in the back from the trunk to back seats but one of them figured out how to tear it down and get into other parts of the car. They also didn't like not having their own space so we put two large size crates from petsmart back there. Dimensions are 36D x 22 W x 28H each. I built a riser to overcome the overlap that I eventually converted to a storage drawer. It's come out really nice (been running it for over a year and half now) and the dogs are very comfortable in the back. Also don't have to worry about them becoming projectiles in an accident.