It was called “the Mexican Road Race,” or more officially, “La Carrera Panamericana.” Held for the first time in 1950, this grueling battle across the new but barely refined Panamerican Highway ran more than 2,000 miles from Juarez south to El Ocotal. Switching directions, La Carrerra headed north from 1951 through 1954. Then it was all over. The toll of human lives (spectators, mostly) during the five races was far too great to continue. Certainly, its brevity locked in the legend of La Carrera, but the brutality of the event was known and even admired from the beginning, attracting OE manufacturers in need of good ad copy. We remember La Carrera mostly for the images of hulking American sedans, plastered with decals, in four-wheel drifts around impossible, potholed curves. There…