Complex sentence: Car production stopped in 1940 and would restart in 1945 under the new name but initially making the pre-war 1.5,2.5 and 3.5 Litre saloons which have become known unofficially as the Mark IV Jaguars.
Split into simpler sentences: Car production stopped in 1940 and would restart in 1945 under the new name but initially making the pre-war 1½, 2½ and 3½ litre saloons. These post war cars have become known unofficially as the Mark IV Jaguars.