- B: Bayerische Motoren Werke, which translates to Bavarian Motor Works
- M: Motorsport, the high-performance division of BMW
- i: Injection, indicating a fuel-injected engine
- x: All-wheel drive
- d: Diesel engine
- L: Long-wheelbase version of a model
- GT: Gran Turismo, a high-performance luxury car
- Z: Roadster or sports car
- C: Coupe
- 4/3/5/7 Series: These indicate different groups based on the size and class.