I recently purchased a 2004 E46 BMW 318 ti M-Sport (Japanese Import) and the motor is N46B20. I believe the first E46 hatch was year 2001 with N42B20 motor. It is also my understanding that 2004 was the last year of manufacturing and then the 1 series was born. Maybe your model was first registered in 2005. By the way I am in New Zealand, where the rugby world cup now lives.