Hi! Thanks for writing in! Well, this definitely sounds like sundowning behavior to me. My first recommendation is to do what you’re doing: avoid going out in the afternoon. Still go out, but stick to morning trips, before his behavior shifts.
I imagine that you’ll have to go out sometime, so this won’t always work. I also assume that his wife can’t always be there. Does it work to call her on the phone? Would it work to tell him that she’s waiting for him?
Your best option, really, is persistence. Keep trying different tactics to get him in the car. I had a resident once who took me 2 hours to get her back in the community. 2 hours. And, really, she was always very sweet…she just sundowned really hard!