This morning I splashed out on a nice, new crate for Zac's car journeys (because he's a pig in the car). I'm going to go gently with introducing him to it but would really appreciate everyone's suggestions for how to make him comfortable and happy to use the crate.
Give his meals in the crate. He will associate it with a happy place to be.
Treats, toys, chew toys, or bones, kongs with treats in them (peanut butter, cheese, dog bones--I freeze my kongs with treats--they last longer).
Turns out he loves his new crate anyway! He had one before and was never too keen so that's why I was worried about getting a new one but he's fine. Went out in it tonight and he's much better in the car - the old crate didn't have the same effect at all but he gets into this new one quite happily and is much calmer. It cost a bomb but was so worth it!