Jay Leno's Bus.
Some, as old as I, may recall early Kawasaki 2 strokes being called Flexible Flyers. Also a popular derogatory remark for many drag racers, be they on 4 or 2 wheels. The term may have started with the production of 'leaning' side cars for motorcycles, manufactured in Ohio in 1914 -20? by the Flxible Co. (sp is correct). Cheap cars in the 1920's left Flxible searching for other businesses. Building hearses, ambulances and small coaches (typically on Buick chassis), led them to larger motor coaches. Flxible built buses in Mexico, South America and China (Roger Penske was involved! As was Charles Kettering of GM fame). Kettering was President for 40 years? and the founder of DELCO. Flxible filed, under Grumman aircraft ownership, for bankruptcy in 1965 iirc.
I drove semi's, doubles and tour busses (as needed), from 1954 to 1967, while going to night school and continued hauling trade shows 'til 1997. Enjoyed nearly every minute of it. In 1955 I drove an yclept 'Band Bus'. It happened to be a Flxible built in the period between 1947 and 1955. Jay's 'Flxie' is very likely of that vintage. The one I drove was powered with a 4-71 Detroit diesel. Super charged 2 stroke fitted with 'hi-output injectors'. R3~