Appropriate technology is not a term that is usually applied to cars, but many of the principles of appropriate technology are relevant.
The W is a rare example of a car that was designed for the poorer segment of society, to be extremely efficient and low-cost. And yet it was also considered a comfortable car, in its own way, with a flexibility that many more expensive cars lacked.
Its remarkable fuel-efficiency is still unsurpassed by modern micro-cars, and perhaps even by the latest petrol-electric W.
The W also had many similar characteristics, though not as extreme, eccentric and efficient.