I don’t recall our cat having so much of a problem with the vet. But it had odd reactions to driving in the car. If we were out in the daylight, it would curl up contentedly on the back seat of the minivan. The one time we took it somewhere at night (I have no recollection of the reason), it jumped up on my back and curled around my neck, latching its claws into my clothing (and my skin). I threw her off once or twice; she climbed back up. I had to drive with a live cat boa around my neck. We figure that she had no problems in the daylight as she could see things going by; but at night the only way she felt like her world wasn’t out of control was to be on me looking out the windshield where at least there were headlights.