I've got a full car seat in the back, but my issue is how to keep him in it. He always wiggles out of his harness or the buckle. This last time I was headed to Deception Pass, next thing I know he was out and half way out the window. I lunged across the passenger and grabbed by his nubby tail with one hand and hit the automatic window upper with the other. Finally made it over to the side and then fell apart. I'm in the boycot carseat stage now. He's calm on my lap but freaks and flips in the seat until he gets out.