the first known street-legal fiberglass dune buggy, "Old Red", the 1st Manx, built on a shortened VW Beetle with a monocoque, fiberglass shell and Chevrolet pickup truck (trailing arm style) suspension, in late 1963 to May 1964 in his garage in Newport Beach, California.

In April 1967, Meyers and his friend Ted Mangels outfitted Old Red with a canvas top, knobby tires, and additional fuel tanks and drove the unpaved route down Mexico's Baja Peninsula - from Tijuana to La Paz - in 34 hours and 45 minutes, besting the previous time by more than five hours.

 The run not only captured the attention of off-road enthusiasts, it also inspired the first Mexico 1000 - the race that would later become the Baja 1000 - which Mangels and Vic Wilson won in another Meyers Manx later that year.

from the mold that made it, 11 more were pulled. 

https://www.hemmings.com/stories/2014/02/19/old-red-the-first-meyers-manx-dune-buggy-to-go-on-national-historic-vehicle-register