Class C or TT to RV with cats? Crate or no crate?

We've taken our cat on several outings this summer. She rides on my wife's lap or sits on the rear sofa when driving. I think she tolerates the driving , but really enjoys it when we arrive. We put her on a lease and she just wants to be near us all day. I also need to qualify this as I believe that this is probably the only cat we have owned that I think this could happen.