What about this Peugeot 504 converted into a tricycle in Syria due to lower taxes? Unfortunately here in Brazil a trike would be liable to a higher DPVAT (insurance for accident victims, not material damage) since it's legally considered more related to a motorcycle...
But anyway, once I got too drunk that I started lurking about doing something similar using the bodyshell of a 2nd-generation S10 Blazer and some small tractor engine (most likely a 1.3L air-cooled inline-twin boat-anchor designed by Hatz and made under license by Agrale).