Thank you everyone for the feedback.
Mom to Hot Rod:
You wrote that Maggie moves around in the Snoozer. I know Max will squirm and work hard to escape -- my primary concern is that the tether will end up wrapped around his neck.

Is that possible? I suppose I need to find a store where I can see one of these seats in person.
I currently have a wire crate in my back seat and I have tried a soft crate. Max hates both, despite having a comfy bed and a great view out the window. He seems excited about going in the car, then he acts panicked the entire time we are driving.