One grand Idea from me, The "Inner Tube"
This would be a vehicle, semilar controll to the Tobbogan, would slide down any slope. This is the change, the mid-air handling needs to be less, almost nothing.
Here's the Best Part, it floats in water too!
A great Multi-Purpose Vehicle that could be used in the Summer and in the Winter, or imbetween...
(for Pool-like inner tubes you would have to have transparent paints work on it)