Do your cats use the litter box while you're on the move/driving?

I'm finalizing my camper's layout and need to decide where I'll be placing the litter box. Do your cats go to the bathroom while you're driving, or do they mostly hold it until you're parked somewhere?

I've thought about making a litter box compartment in the rear "garage" with cat door access, but my cat might not like the noise level back there when we're on the road. If he'll be using it when we're moving, I'll build him a cubby up closer to the cab area.

I'll know more about my specific cat's preferences when we start taking trips this spring. I've driven long distances with him when we moved states, but I don't think he touched the litter box until we got to the hotel each night.