What's the worst that could happen if the grill is not big enough for the speaker? There are some 6.5" speakers in it now. The actual opening in the metal is 5.5" though so I'm guessing the speaker size is measured from the mounting points?
Oh cool thanks. It's a 1990 Mazda Miata. I currently have a 50x2 rms JBL amp to drive them but if I can get it cheap enough I'll be getting a 75x2 rms bazooka amp.
I checked crutchfield.com and they said these wouldn't fit in my car. Could you measure the diameter and depth so I can check car and see if they will work?