Well I bought the little seat belt thingamajig that attaches to the harness. PetCo sucks. They didn't have anything so I went to PetSmart. We'll see how it works. I hope it's short enough to secure him but long enough so he can be in his cubby or he can move to the seat next to his cubby (sometimes his cubby is in the sun and he doesn't like it so he moves to the seat next to his cubby and sleeps on his blankie).

This is what I got Fenway: