Audi A6 1994–1997 Transponder KeyC4 Audi A6 1997–2004 Remote KeyC5 (ID13, 97-98) Audi A6 1997–2004 Remote KeyC5 (ID48, 4D0) Audi A6 2004–2011 Smart KeyC6 Audi A6 2004–2011 Remote KeyC6 Audi A6 2011–2018 Smart KeyC7 Audi A6 2018–2025 Smart KeyC8 Audi A6 2025–2026 Smart Key4L