After building the LEGO Technic Quad Bike 9392, I looked at the model and thought that the orange colored panels could be used to make a Vespa Scooter.
There are 2 longer orange panels and 2 shorter ones. The longer ones could be used to create the side panels of the scooter that covers the engine and spare tire. The shorter panels could be used for the front of the scooter.
In the set, there are also 2 angled orange colored technic beams. These orange beams could be used to form the lower chassis linking the front to rear of the scooter.
The wheels in the Quad Bike 9392 were too large so I used the smaller wheels from the Go Kart 8256. Besides the wheels, all parts can be found in the Quad Bike 9392.
Entire process took about an hour including dismantling the built Quad Bike and swapping parts around as I went along to build the scooter.
I ran out of orange colored parts to make the cover for the front wheel and I’m sure there’s lots more ways to improve the current design.