This do it yourself video shows how to replace spark plugs on 2005 BMW M3. This procedure is pretty much the same on all 3 series e46 chassis. The spark plugs that BMW uses on M3 models are NGK DCPR8EKP or Bosch FGR8KQC. I used NGK. You can get them from Advanced Auto Parts for $13 a piece where as BMW charging you $26 for the exact same spark plugs. Not that other non-M3 e46 models use different model spark plugs.