Perhaps the previous owner installed a bypass module (cheap on ebay) so as to not get the airbag warning light come up (used to be common fault on E46). Have you not had the car into BMW recently from the letters they sent out about the airbag recall?
The seats do not have airbags in them, only the dash, doors and pillars do.
The seats do not have airbags in them, only the dash, doors and pillars do.