So, for getting him in the car. Do you have a four door car? if so, open BOTH back doors, and put a rope or leash through one door, and out the other. Get Bison near the door, on the leash, and pull him through the car first, so he just goes in, walks through, and then comes out the other side. Your son or grandson can help with this perhaps the first time. After doing that a couple of times, get him in the car, shut the door, and trap the leash in the door, effectively using the leash like a seat belt to keep him in the back seat. Sit with him, read the newspaper, or check your phone. After a bit, without acting like it's a big deal, let him out. Don't drive anywhere the first couple of times you do this. Feed him in the car, give him treats, but don't go anywhere for a bit. After he is getting into the car readily, take him for a short car ride, like down the block, and get him back out. He needs to know that it's just a fun thing to do to go for car rides. Try that out and let me know how it goes!!