what size spacers on stock 18s

want to get spacers on my coupe, was wondering what spacers i should get to make my wheels look flush. i am running stock 18s right now
pics are greatly appreciated

also will i have problems with the wheels being under the fenders? im not sure but since im on stock suspension im assuming it should be fine...?

Check the big spacer thread.

got it. was looking for it last night but couldnt find it but i looked again now and i got it
if anyone's curious about this here's the link http://www.m3post.com/forums/showthread.php?t=336209