Sherry and I switched off driving home, with the other one sitting in the back seat with Chimera. Normally I have my dog ride in a crate, but Cai hadn't been crate-trained yet and it would have been a very long trip in a tiny space, so we let him wander a bit. He would repeatedly go to the window and get upset or excited and start whining and jumping up. We would redirect him and he'd calm down again quickly. He spent most of the journey sleeping, though he was constantly shifting from place to place.
Jacques sat in his booster seat in the passenger seat. When Sherry was sitting behind him he'd want to get into the back with her. Then he'd realize that the Puppy Monster was still there, and he'd want to escape to the front again.
We stopped a few times to let the dogs stretch their legs and potty. Chimera was on leash for the first time, but I mostly followed behind him and didn't let him hit the end of the leash. We did some recalls to "pup pup pup pup!!" and he would excitedly run over to me for scratches and a treat. During our rest stops we saw a some people, a couple of other dogs, trucks, and Cai walked over grass, dirt, and leaves. He took everything in stride and was eager to walk around and explore. Excellent.
Toward the end of the trip when he was really tired, we put him into a crate, and he shifted around but slept for nearly three hours. Sherry and I patted ourselves on the backs, thinking that he would be easy to crate train. (Insert ominous music.)
I drove to Sherry and Jacque's house first to drop them off. Again we let Cai out to pee and poop and run around. Then I put him in his crate. And he started screaming. That terrified, primal puppy screaming that means "I'm am absolutely sure that I am dying/about to die."
I moved the crate from the back into the passenger seat, put my hand through the bars, and talked to him calmly. After two or three minutes he calmed down and started to doze off, and the rest of the trip was thankfully quiet.
We got home and I put Jasper Kitty into the bathroom, unloaded my things, and brought Cai into his new home. He sniffed around, and then I put him into his pen so I could unpack. Again with the screaming. So I moved him around the apartment with me, gating him into whatever room we were in. Any time I put a barrier between us, he would scream. At bedtime I placed his crate onto my bed, put my hand through the bars again, and fortunately he was tired out and only shrieked for a few minutes before he gave up and passed out.