Though it was sold in America for just three model years (1983-1985) the original quattro (a.k.a. "ur quattro") was produced for over a decade (1980-1991). Outwardly, it only received one freshening, which would include minimal changes most notably spotted as sloped rather than vertical grille and headlights or the slight lip on the car's iconic Ronal wheels.
The car is certainly more mysterious given no examples are known to exist. Additionally, the RS 001 story reads like a spy novel from the start to its untimely demise.