a few 80's and early 90's cars wich had quite good to exeptionally good Cd's used these cut off rear arches... unfortunately big wheel arches again became a fashionable in the late 90's and this smart feature disapeared.
here's a few examples of car wich more or less cut off rear arches... most have pretty great aero for their age
1986 opel omega 0.28 Cd (one of my favourites)
1984 opel kadett (later rebadged daewoo nexia and pontiac lemans) 0.32 Cd
1983 citroen bx 0.34 Cd
1986 citroen ax 0.31 Cd
1996 Smile (greenpeace converted renault twingo) 0.25 Cd (compared 0.35 for the original twingo)