Solution

Yesterday, I had to let him in the side door to get to doggie park. This morning, he started running to the front of the car when I wanted him to jump in. I called him back and told him to jump. Again, he ran to the front, then all the way around the car, then jumped in! That’s it! He has to run around in a circle before he can jump – at least, when he is frightened. That is a doggie rule in the book somewhere.