The CS stood for Coupe Sport. The 2800 CS and subsequent models featured a new front end that would influence BMW design for many years. The style of the C-pillar with the Roundel logos are unique to the CS models. My first CS was a 2800. The biggest problem is rust. It is very difficult to find one that is not rusted. Restoring a rusted car is, additionally, very expensive and, until these cars are north of $100,000, repairing one to a highly restored level is prohibitive.
The 2800CS had the new 170 hp 2.8-liter single overhead cam (SOHC) six-cylinder engine designed by Alex von Falkenhausen. Although the four-door models like the 2500 and 2800 used rear disc brakes, the new 2800CS had rear drum brakes. The new CS was available with a four-speed manual or a three-speed ZF automatic transmission. The automatic was not well-received by the press, and it was soon replaced.