Complex sentence: Originally, the name "Audi allroad quattro" applied to a semi-offroad version of the Audi A6 Avant (wagon) in 1999, with subsequent generations released in 2006 and 2012 retitled "Audi A6 allroad quattro".
Split into simpler sentences: Originally, the name "Audi allroad quattro" applied to a semi-offroad version of the Audi A6 Avant (wagon) in 1999. Audi retitled subsequent generations, as released in 2006 and 2012, as "Audi A6 allroad quattro".