anyone consider the flex from the front windshield is what causes it to vibrate so much?

Mirrors shake will shake, and subs cause this.

Just a fact of life.

lol exactly, its not a prob;lem with how tight it is,its just vibrating from the bass! im just trying to stop that

LOL, I don't think that the dynamat will do much. But it was a good idea.

twas afriad of that, also thought it might look stupid lol... any ideas anyone?

I did the Dynamat on the back of the rearview mirror and it helped quite a bit. I put two pieces on each side of the rearview mirror. Just make sure you pick pieces that do not have the Dynamat logo. Get the Dynamat "original" which has a dark backing (i.e. it isn't shiny like the other Dynamat).

Try and pick up some scrap from a car audio shop.

It doesn't solve the problem 100% but its better than nothing.

FYI my non-dimming mirror didn't shake, but my dimming one does....

hmm thats not a bad idea, the orignial might work. i have tons of extreme here. is dosent weigh it down at all does it?

Jam a piece of paper in there. It just gets annoying when it starts to rattle and makes a squeky noise