Obvious possibly, but having seen teh problems on the race car when we started to strip it yesterday worth mentioning.
Don't cover teh drain holes at the bottom of your doors when installing Dynamat or similar inside your door panels, it was like a swimming pool in there.
Not a good plan unless you want to rot teh doors from teh iside out
To add to this make sure you have the side protectors on the speakers like the stock brackets do or they'll get wet too on a regular basis.
For anyone at last years ding day that I helped install - I did not cover the holes on yours the same as i didn't on mine so don't worry!!!
I had seen them on mine and thought it woul be an extremely bad idea to cover them up - can't remember who I helped though, hopefully you can!!!!