The general consensus in the RVing community is that towing with all 4 wheels down is ideal. The setup requires a base plate that is mounted on the tow vehicle (aka dinghy, towed, toad) and a tow bar on the motorhome. They're easy to connect the two and whenever the vehicle isn't being towed you can either remove and stow the tow bar or leave it connected to the RV. The downside is that all base plates are not created equal, if you switch toads then you may have to buy a different base plate, plus there are a number of models of cars that require some body modification before a base plate can be installed. There are also a number of models that require no alteration and are reportedly a dream to tow this way. Jeeps seem to be a favorite.
If you don't purchase a tow bar with surge brakes then you'll (probably) need to buy a supplemental braking system that ties into your toad's brakes so that the push of your tow vehicle doesn't significantly reduce your RVs braking ability. I say probably because there are differing opinions on that. I just think, for me, I don't want to add push weight to the back of my RV and not compensate for it some way. Even if the stopping distance isn't reduced by a lot, that little difference could mean the difference between an accident and a close call. There are also some states that require a supplemental braking system, though enforcement is reportedly spotty.
An alternate way to tow is with a tow dolly. The tow dolly takes the drive wheels off the pavement. Front wheels up on a FWD toad, back wheels up on a RWD. Some tow dolly manufacturers say never to pull a vehicle backwards (maybe because that puts all that engine weight at the very end and could cause a sway problem, I'm guessing, oh and you'd have to secure the steering wheel somehow so the wheels don't swivel freely) but there are people who 'do it all the time' without issue. A benefit of a tow dolly is you don't have to modify your toad, and switching toads doesn't mean any additional expense as far as the dolly is concerned.
We have and love a Toyota Prius. After much researching, discussion and price comparisons, we decided to keep the Prius and buy a tow dolly rather than sell her to buy something we can tow four down. Tow dollies can be very expensive but there are a couple of American companies offering them for around $1,200. One is the EZE-Tow and the other the American Car Dolly. We were going to buy the EZE-Tow because it has surge brakes but then found a local guy on craigslist who was selling his used Car-Tow for $800, so we snatched it up. It has surge brakes, too. He hooked up our Prius to show me how it was done (a spotter directs the driver as she pulls the car up onto the dolly then the tires are securely ratcheted down and chains attached) then pulled it around his property while I walked behind watching. Since the ramps do not remove from this dolly, I wanted to make sure they wouldn't smack the underside of the car. They don't. :0) You don't have to do anything special with the Prius while it's on a tow dolly. There's no steering wheel column lock on the Prius, hence nothing to unlock to allow the wheels to trail nicely as you turn corners. Just put it up and go.
We had a hitch receiver installed on the Prius at our local U-Haul so that we can tow the dolly if needed, and that's just how we got the dolly home.
If you're considering a tow dolly, you should know that they're heavy (400-500 pounds) and not very easy to move without help. I can move ours by myself but it's a struggle and I wouldn't be able to move it very far or over rough terrain. You can buy a little trailer dolly to help with this but we'd like to keep 'stuff' to a minimum so I won't go that route unless it becomes necessary down the road.