Having spent many years ribbing / towing to SW France for hols. plus rubber ducking with various yachts I have come to the conclusion that the smaller "car-toppable" ribs etc. have too many drawbacks, most importantly the time it takes to get on-the-water. Ther are several companies that make small and/or collapsible ribs such as Bombard and Tinker. Your maximum size for this type of rig is likely to be 3.2m. If you are only doing lake stuff with one or two people close to shore these may be worth looking at, but I have some poor experience of the removable-floor type ribs - the water seals just arent up to any great amount of abuse. At least the removable floor inflatables dont have any floor leak problems. I now put up with towing a rib rather than folding or roof-topping. Not only do you get a "proper" boat but you can also be on the water and going in minutes, plus the boat/trailer doubles as a gear trailer for holidays!