Implement the Car Accident OOBN, then extend it (along the lines of Example 4.3 in (Koller and Pfeffer, 1997a)) with subclasses to mode:

 a fuel-injected engine (a subclass of ENGINE), which is less reliable and is more likely to provide a high power level;

 a sport-car (a subclass of CAR) with a fuel-injected engine, a higher original value, and has a new output node Acceleration that is a function of the engine power and the original value.