Question: What was a previous unoffical name for the high performance variant of Audi's compact executive car?

full_context: Document 1: Audi S5: The Audi S5 is the high-performance variant of Audi's A5. It is also the coupé, cabriolet, and five-door fastback versions of the fourth-generation (B8) Audi S4 saloon and estate models.
Document 2: Audi RS 2 Avant: The Audi RS2 Avant, usually known as Audi 80 RS2, was a limited edition, high-performance Audi five-door, five-seat estate car (station wagon), manufactured from March 1994 to July 1995. Collaboratively designed as a joint venture between Audi AG and Porsche and built on Audi's 80 Avant, designated internally as P1 (instead of B4/8C that it was based on). It was Audi's first "RS" vehicle, and the first of their high-performance Avants (Audi's name for an estate car or station wagon); it used the most powerful and most thoroughly developed version of Audi's inline-five cylinder turbocharged internal combustion engine.
Document 3: Audi A6: The Audi A6 is an executive car made by the German automaker Audi AG, now in its fourth generation. As the successor to the Audi 100, the A6 is manufactured in Neckarsulm, Germany – and is available in sedan and wagon configurations, the latter marketed by Audi as the "Avant." Audi's internal numbering treats the A6 as a continuation of the Audi 100 lineage, with the initial A6 designated as a member of the C4-series, followed by the C5, C6, and the C7. The related Audi A7 is essentially a coupé-hatchback version of the C7-series A6, but is marketed under its own separate identity and model designation.
Document 4: Audi RS 4: The Audi RS4 quattro is the top tier and highest performing version of some specific generations of the Audi A4 range of automobiles. It is a sports-focused compact executive car (often called sport compact in some countries ), produced by Audi's high-performance private subsidiary quattro GmbH, in limited numbers, for German car manufacturer AUDI AG, part of the larger Volkswagen Group. It slots distinctly above the Audi S4, as the fastest, most sports-focused model based on the A4's "B" automobile platform. The RS 4 made a comeback in 2012, in Avant form only based on the Audi A4 Avant.
Document 5: Audi V8: The Audi V8 ("Typ" 4C) is a four-door, full-size luxury sedan, built by Audi in Germany from 1988 to 1993, as the company's flagship model. It was the first car from Audi to use a V8 engine, and also the first Audi to combine a quattro system with an automatic transmission. Early cars used 3.6-litre V8s, while later cars featured a 4.2-litre version of the engine. The Audi V8 was replaced by the Audi A8 in 1994, although the A8 was not sold in North America until 1997.
Document 6: Porsche 968: The Porsche 968 is a sports car made by Porsche AG from 1992 to 1995. It was the final evolution of a line of water-cooled front-engined rear wheel drive models begun almost 20 years earlier with the 924, taking over the entry-level position in the company lineup from the 944 with which it shared about 20% of its parts. The 968 was Porsche's last new front-engined vehicle before the introduction of the Cayenne SUV in 2003.
Document 7: Audi Q7: The Audi Q7 is a full-size luxury crossover SUV of the German manufacturer Audi, unveiled in September 2002 at the Frankfurt Motor Show. Production of the Q7 began in autumn of 2005 at the Volkswagen Bratislava Plant in Bratislava, Slovakia. It is the first SUV offering from Audi and went on sale in 2003. Later, Audi's second SUV, the Q5, was unveiled as a 2009 model. Audi has since unveiled a third SUV model, the Q3, which went on sale in the 3rd quarter of 2011. The Q7 shares its platform and chassis with the Volkswagen Touareg and the Porsche Cayenne.
Document 8: Audi S6: The Audi S6 is the high performance variant of the Audi A6, an executive car produced by German automaker Audi. It went on sale in 1994, shortly after the "A6" designation was introduced, replacing the "100" nameplate.
Document 9: Audi Q5: The Audi Q5 is series of compact luxury crossover SUVs produced by the German luxury car manufacturer Audi from 2008, The original first-generation ("Typ 8R") model was the third member of the "B8" family to be released after the Audi A5 and fourth-generation A4, all being based on the Audi MLB platform. The second generation Q5 ("Typ 80A") debuted in 2016 and shares the Audi MLBevo platform with the corresponding "B9" versions of the A4 and A5.
Document 10: Volvo S40: The Volvo S40 is a compact luxury car marketed and produced by the Swedish manufacturer Volvo Cars from 1995 to 2012 across two generations.
Document 11: Audi Ur-S4 / Ur-S6: Audi Ur-S4, and Audi Ur-S6 were unofficial names for the original models of the Audi S4 and S6 automobiles.
Document 12: Audi S4: The Audi S4 is the high performance variant of Audi's compact executive car A4. The original Audi S4, built from 1991 until 1994, was a performance-oriented version of Audi's 100 saloon/sedan. All subsequent S4s since 1997 have been based on the Audi A4; and as the A4 has evolved from one generation to the next, so has the S4.
Document 13: Audi A4 DTM: The Audi A4 DTM is a 4-door touring car (DTM) constructed by the German car manufacturer Audi. It was first developed for use in the 2004 DTM season, replacing the Audi TT DTM at the end of the 2003 DTM season. Based on the Audi A4, it was continually improved over the course of six facelifts between 2004 and 2011. The Audi A4 DTM was succeeded by the Audi A5 DTM in 2012.
Document 14: Audi allroad quattro: The Audi allroad quattro is an automotive nameplate used by the German automobile manufacturer Audi since 1999. Audi has utilised the name "allroad quattro" to signify semi-offroad ability on two of its mainstream model lines. The main differences between the allroad and the base model are a wider track (made possible by plastic wheel arch extensions), higher ground clearance and adjustable air suspension.
Document 15: Audi 80: The Audi 80 is a compact executive car produced by the German manufacturer Audi (initially known as Auto Union and Audi NSU Auto Union) from 1966 to 1996. It shared its platform with the Volkswagen Passat from 1973 to 1986 and was available as a sedan, and an Avant (Audi's name for a station wagon). The coupé and convertible models were not badged as members of the range but shared the same platform and many parts.
ground_truth: Audi Ur-S4