Speaker Dampening

I have a mitsubishi eclipse (2 door 2 side panel backs) and I am going to be putting in some 2 way alpine type r-s in the doors and back panels (6.5 and 6X9).  I was wondering as far as those dynamat (or whatever other brand) speaker kits would be worth my time or money for a noticible performance difference.  Im talking just the square that goes where the speaker will be installed.  Any opinions?  I know it will strengthen that part of the door some....but it has been a pain finding local dealers in san diego that sell just the speaker kit, so Im wondering basically if it is worth my energy to track some down for my install.

Thanks

Thorough coverage of all the sheet metal with a layer of damping is far more important than the square waffle piece.  Chances are greater than not that the door skin is not parallel to the speaker mount location, so the effect that the waffle is supposed to dissipate may not occur at all.  That is, the back waves bouncing directly back through the speaker.  I used the squares in my car just to try them, though.  But one would have to do some on and off testing with the same car, same speakers to know for sure if there is a noticeable difference.  Since these are adhesive-backed, you can't do very thorough testing but you could install the Dynamat first without it.  Who's going to go through all that putting the door back together completely sealed and then taking it back apart to install the square just to see if it makes it sound better?

I would suggest buying the damping in bulk and foregoing that expensive waffle square.  You could add it if you experience less-than-stellar results.