Within this haze, an unusual model quietly surfaced in the early 1990s—the Audi 100 RS4. Despite sharing its badge with the later and far better-known B5-generation RS 4 Avant, this prototype was entirely different.
Audi returned to the DTM for 1991 with a slightly updated V8 quattro Evo. Hans Joachim Stuck would lead the squad with the #1 car, though a young upstart new to the Audi brand if not the series was Frank Biela.
Having had quattro deemed an "unfair advantage" and thus outlawed in Trans-Am in 1988 and IMSA GTO racing in 1989 for its on-track dominance, Audi Sport turned to the German DTM series.
Built at the insistence of Ferdinand Piëch as a fully functional, road-approved family car for his wife Ursula Piëch, it remains one of the most unusual and storied vehicles ever produced by the brand.
