@ doughboy many thanks! so stupid, i never clicked on the photo icon...
from realoem I only visited :
RealOEM.com Home => Select another car => Engine electrical system => Ignition system => IGNITION COIL/SPARK PLUG
in which you can see a generic icon of a 12 point spark plug...but if you click on the icon in the right of the index, then you see the true image of a regular hex spark plug...the one you also posted here!
i have found my spark plugs from ebay, ngk laser iridium IZFR6H11 about 9 each. i believe is the cheapest till now
@ wallsmk2 thanks for the info mate.
E90 Montego Blue 320i N46B20