My car isn't big enough to hold a crate that Apollo would fit in (Dodge Caliber), much less a 2nd crate for Arty. Plus Apollo gets carsick if he rides sideways on the bench seat. We got a pet barrier to keep them from climbing into the front, fold down the back seats, and got a zipline restraint that attaches to the rear of the trunk area. Its not perfect, in a side impact or a rollover it wouldn't help. But in a front or rear impact it would, and it keeps them from trying to climb out windows and the like. Our next car is going to be bigger...