The Airstream Basecamp is cool. I saw one of the factory demo's at a park while mountain biking. Unfortunatly about the only cat you can carry is an A-Cat on a roof rack. The factory rep mentioned they could build a larger version.

One of my regrets is turning down an old Airstream trailer with a flood destroyed interior from a relative. With a rear opening hatch, that would be a nice way to carry my A-Cat (and a disassembled Tornado)