Engine boss Wolfgang Hatz told Automobilwoche that the VW subsidiary will be using the technical base of the A4 for at least two more derivatives.
Audi officials say a compact off-roader and a sports tourer, following the example of the Mercedes R class, are being considered.
There might also be an addition to the TT family. A "shooting brake," a two-door version with large hatchback, might join the sports coupe and the roadster models.
Audi's chief designer, Walter de' Silva, says: "It is more than just an idea." Hatz also believes that "such a car would be possible."
Audi first will decide within the next few days whether the Allroad Quattro concept car based on the A6, which was presented at Detroit, will go into series production.
Ulrich Hackenberg, head of concept development, says that the reactions to the concept car, which was developed in only three months, were very positive.
He believes that the Allroad Quattro will go into full-scale production. "So far every show car designed by me was built."