If that Vibe (Toyota Matrix) has a manual transmission it should be a very good toad. The way the tow bar mounts onto the base plate on the towed vehicle, and the height of the hitch receiver on the coach, determine your amount of drop. You need to get to where the tow bar is within three inches of level when hitched and both vehicles are on level ground.
Let's say your coach hitch receiver is 24" off the ground and your Vibe works out to 14" that's a 10" difference. A 7" drop would get you within 3".
Look up base plates for your Vibe (maybe under Matrix) on the web for the popular brands of Blue Ox, Demco, and Roadmaster. I think Demco includes installation instructions. I know the other two do, and they include a photo of the car once the baseplate is installed. That'll give you an idea of the drop you'll need. At least those three offer towbar adaptations to use other brands' base plates, so you can pick what seems to fit best.
The Ready Brute Elite towbar from Night Shift Auto offers a built-in braking system that makes it very special, and they offer connections to the various base plate brands.