Post WW11 Touring car racing in Australia originated with many of the cars being ex Taxis.
Cheapest vehicle you could get hold of to modify and usually not as old and rusted as other cars reaching their economic life span.
Even before the Geoghan and Myer Holdens there were Ford V8s and even more early 40s Dodge 6's.
Can someone look up the Mt Druitt records for a 42 Dodge with the then tell tale ex-cab paint job of black with orange guards.
They filled the need for cheap and frequently spectacular racing.
Tongue in cheek may I suggest we sart a series for ex-cab Prius.
Ticks all the boxes from a cost and tradition basis