I am not sure if I will be of much help but I can try. I have done a 16 hour drive move with dogs and cats but not rabbits. You could invest in a bigger carrier that can fit in your car that might hold a small litter box. I have a carrier for my rabbits that has a food and water tray that clips on the carrier door perhaps you can find something like that. As for keeping him from overheating at rest stops perhaps you and your spouse can take turns getting out at rest stops so you can leave the air conditioning running . Long car trips are not the greatest of experiences but I am sure you can make something work. Best of luck!

We moved Coco and Jackson from Montreal to Wisconsin in July of 2012. I drove with the rabbits, my husband drove with the cat.

My car did not have A/C.

I used the a Large Living world type cage with a hard plastic bottom and the open wire style top for good air flow. I set them up with their normal litter on bottom. I had water available but they didn’t drink. They had the entire back seat of our car.

The first day ( 6 hours) we drove at night and stopped at a pet friendly hotel. I immediately got them out and into the bathroom of the hotel, set up their greens ( with extra dampness) and water. They did great. I saw poo and urine in the litter box in the AM before they went back into the car cage.

I always had damp greens ready for them and in the cage, but they never ate (that I saw) while in the car.

We made another 8-9 hour drive and stopped at another hotel. It was brutally hot that summer. I found that buying bags of ice and settling them (2 bags- one per rabbit) that it was able to keep them from keeling over in the heat. I will note that Coco had a much harder time and I worried endlessly about her in the heat.
They would each tuck themselves on top of or next to the bags of ice. Coco would lick the water off the plastic bags as the ice melted.

We made three legs to the trip, with a pet friendly hotel at each end of day. This way I could make sure they were pooing and urinating.

Organization will be crucial. I had a large bag of Hay, a cooler for the greens I would refresh daily, and my emergency bag of critical care, metacam, treats etc. You’ll also need a large bag of litter to be cleaning the litter daily. I also used extra little boxes that would be hauled into the hotel room at night, then could be repacked in the car.

Remember, I also had a cat in another vehicle who had his own litter/food/water needs. We looked like a circus every night.

I did keep a light towel on top to make sure they weren’t getting pelted by the sun. I wanted to make sure they had good airflow because it was 100+ degrees every day.

One of the reasons I broke the trip into legs was my fear of having the buns stop eating or drinking.

Just make sure he’s never in the car alone-if you have to leave him in there, leave it running with AC on and make sure you can see it (i.e. park right outside the window of the restaurant, that way you can ensure the car is still running; if you have a car starter this is easy, you can lock it and leave it running).

You can tape sheets/pillow cases (or purchase traditional car window sun blocking blinds) for the trip so he’s not in direct light.

He could certainly stay in the carrier for the duration. 12 hours isn’t so long, and the good news is with that long of a trip he’ll have plenty of time to habituate to the car-you may be surprised to find he sleeps!

When I did one long road trip, I kind of stuffed items into the recess between the floor and seats, so that they had the whole back seat, and I had the bottom of the carrier as like a home base/litter box. I rigged up a water bottle, and took veggies and hay for them. Then at rest stops I force fed a few syringes of apple juice mixed with water and critical care, just to make sure we kept food in their tummies. It was actually really easy and they did just great (trashed a hotel room though! If you have a stop over I recommend a hand broom so you don’t have to sweep hay with your hands!!)