Montana didn't do a full rear. He would lift his fronts up a good foot or so and come back down immediately. I honestly think he was more scared of the trailer than anything.
I rather not use a bit or a chain or anything like that to get him in. I want it all to be a nice positive, calm experience for him.
My friend did try the whole whip his heals to get him to move and that didn't work.
I did not have a chance today to work with him in tight quarters, but I hope to soon.
He doesn't have a problem going through a small opening (gate or stall door) but it could be because he knows after that small space it gets larger.
I did not go over any bridges while on the trail, but we did have to squeeze through two trees and posts quite close together. I was obviously more concerned about getting my knee hit (again) than he was about going through there.
I do have a blue tarp I can use, and I'll see what else I can use to help.
I'm probably not going to get help from a trainer because he does load.. it just takes 20-30 min for him to realize there is no monster in there. If for any reason, I feel I am in over my head and have exhausted all my other options, I will get help from a trainer.