crate training

We are moving next week. It will be at least a 4 hour trip with the kitties in their crate. Last time I took them to the vet Jack became frantic. So I have the crate set up in a central location and the door is open. Every day I will put them in there for a few minutes with the door shut and every couple of days I will pick it up with them in it and walk around.
Any other ideas to make Jack more comfortable with it?
Raven was fine.

Sounds like your on the right track I would also give him Rescue Remedy or another calming essence like Emergency essence and spray the carrier with Feliway.