This is all the Audi A4/S4/RS4s in the US, I've mentioned twice 2 separate A4s listed as 1999 models when they are 2000-2001 models with my comment being deleted. I made this probably since most of the admin are European and don't use the North American Model Year system.

B5
1996-1999 AWD Sedan [PFL]
1996-1999 FWD Sedan [PFL]
1998-1999 AWD Avant [PFL]
1998-1999 FWD Avant [PFL]
2000-2001 AWD Avant [FL]
2000-2001 AWD Sedan [FL]
2000-2001 FWD Sedan [FL]
2000-2001 S4 Sedan [FL]
2001 S4 Avant [FL]

B6
2002-2005 AWD Avant
2002-2005 AWD Sedan
2002-2005 FWD Sedan
2003-2006 FWD Cabriolet
2004-2005 S4 Avant
2004-2005 S4 Sedan
2004-2006 S4 Cabriolet

B7
2005-2008 AWD Avant
2005-2008 AWD Sedan
2005-2008 FWD Sedan
2005-2008 S4 Avant
2005-2008 S4 Sedan
2007-2008 RS4 Sedan
2007-2009 FWD Cabriolet
2007-2009 S4 Cabriolet
2008 RS4 Cabriolet

B8
2009-2012 AWD Avant [PFL]
2009-2012 AWD Sedan [PFL]
2009-2012 FWD Sedan [PFL]
2010-2012 S4 Sedan [PFL]
2013-2015 Allroad [FL]
2013-2016 AWD Sedan [FL]
2013-2016 FWD Sedan [FL]
2013-2016 S4 Sedan [FL]

B9
2017-2019 Allroad [PFL]
2017-2018 AWD Sedan [PFL]
2017-2018 FWD Sedan [PFL]
2018 S4 Sedan [PFL]
2019 AWD Sedan [FL1]
2019 FWD Sedan [FL1]
2019 S4 Sedan [FL1]
2020 FWD Sedan [FL2]
2020-2024 Allroad [FL]
2020-2024 AWD Sedan [FL2]
2020-2024 S4 Sedan [FL2]