Cool things with wheels since 2006
It's a good idea, but I wouldn't want to have to smell the litter box all day long in the cab.
as a cat guy, I can vouch for the incredible ability of good cat litter to completely erase all smells... and it's great in case you need oil absorber, or traction aid. The cheap stuff is useless, but the good stuff is astonishing
and cats only crap about once a day, if you stick to feeding them dry foods, and chicken, turkey, beef, but avoid all fish, they are far less smelly. Fish is to be avoided.
We've had a cat for a year now, and you're right that the litter does a good job of covering the odors. I'm the one who has to clean the box, so I guess I'm a little more sensitive to it. Our cat would probably be a good travel companion. She would love looking out the windows at everything going by.