Yes dynamat in the front doors will help, my car is having it's install done imminently and dynamat is already on the list. Yes it does make that much difference, (if used in the correct places).
Standard speakers are crap, (sorry, too opinionated), they are of a very basic quality and not capable of giving good quality sound reproduction.
If you want to improve your system, changing to OFC wire will help and upgrading the speakers will help also.
"Hop on Baby"
Mike