"BMW is fortunate--we don't have too much of a dilemma as to what we're going to call our cars." McDowell (vice president of marketing for BMW) is referring to BMW's trademark naming system that consists of the product line number and the motor type. For example, the designation "328" tells you the car is in the 3 series and the engine is 2.8-litres in size. BMW has found this naming system to be clear and logical and can be easily understood around the world. The Z and X series don't quite fit in with this system. BMW had a tradition of building experimental, open-air cars and calling them Z's, and hence when the prototype for the Z3 was built, BMW decided to continue with the Z name. For the sport activity vehicle, BMW also used a vehicle didn't fit with the sedan oriented 3, 5, and 7 series. Other then the Z3 (the third in the Z series) and the X5 (named 5 to symbolize its mid-sized status within that series), the BMW branding strategy is quite simple, unlike the evocative names many car manufactures choose to garner excitement for their new modals.