The problem apparently involves a potential leak in the fuel line, which, as any mechanic or McGuyver fan could tell you, is not such a good thing. As NHTSA points out, it "may result in a fire."
The recall involves 3,594 vehicles in these United States, specifically model-year 2013 and 2014 Audi S6 and S7 models equipped with the 4.0-liter twin-turbo V8. (It does not, however, seem to affect the S8 or any of the Bentleys that are powered by the same engine.) Owners of said cars can expect to be contacted regarding how the problem will be fixed. In the meantime you can read the official notice below.
Report Receipt Date: SEP 23, 2013
NHTSA Campaign Number: 13V450000
Component(s): FUEL SYSTEM, GASOLINE
Potential Number of Units Affected: 3,594
Manufacturer: Volkswagen of America, Inc.
Volkswagen Group of America, Inc. (Volkswagen) is recalling certain model year 2013-2014 Audi S6 and S7 vehicles equipped with 4.0L engines. Due to manufacturing tolerance issues, a fuel line may leak fuel.
A fuel leak, in the presence of an ignition source, may result in a fire.
Volkswagen will notify owners, and dealers will replace the fuel line, free of charge. The safety recall is planned to begin in late October 2013. Owners may contact Audi of America at 1-800-822-2834. Volkswagen's number for this campaign is 20U6/L8.
Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.safercar.gov.