Fuel Tank Filler Cap Fits for 2005-2009 Audi A4 2005-2009 A4 Quattro 2006-2011 A6 2005-2011 A6 Quattro 2006-2013 A3 2006-2013 A3 Quattro 2007-2008 RS4 Replace 1K0201550G 1K0201550Q 4F0201550B
Function: Locking fuel cap seals the filler neck to prevent vapor loss, maintain tank pressure and stop fuel from sloshing out during sharp turns or sudden stops
Installation: Twist the old cap counter-clockwise to remove, align the new one until the threads bite, then turn clockwise by hand until you hear several distinct clicks