Some bunnies are fine, while others really get stressed out. Four hours is not that long, and he should be fine, but just keep a watchful eye.
Here are some tips from the House Rabbit Society. Some of the tips are meant for longer, cross country rides, and some you’ve already thought of, but there are some useful tips that are also valid for short trips:
"If your rabbit is not used to car rides (except to the vet), start regular car rides as early as possible before your actual trip. Start with short (30-minute) weekly or twice weekly rides in a pet carrier. Try to have some longer rides (1-3 hours) before the trip. Remember, don’t leave your rabbit in a warm car
About Car Travel
- Rabbits cannot tolerate heat.
- If you have no air conditioning, drape damp towels over the cage and give frozen water cartons to lie against
- Don’t leave your rabbit in a parked car in the sun. You may have to get food-to-go, take food along and stop in shaded rest areas, or wait until early morning and late evening to stop to eat.
- Rabbits do not like drafts. Carriers should not be placed where AC/heat blows directly on them.
- Water bottles will often leak out all their water. Rabbits tend to not drink while traveling, so offer water at all stops. Add Pedialyte to combat dehydration, but be sure the rabbit will drink it. You may have to syringe/dropper-feed water.
- Rabbits may also not eat while traveling. Offer favorite vegetables, pellets and hay at all stops. Put some hay and pellets in carrier while traveling.
- Even if you don’t usually feed pellets, you may want to make an exception for traveling. Carrying enough hay for proper nutrition can take a lot of space. Instead, supplement the fiber of some hay with the calories in pellets.
- Try to establish some routine as to length of time in the car each day, stopping times, feeding and exercise times
- Strap down carriers so they do not slide during sudden stops"
Let us know how it goes and have fun!