I had Dynamat installed on my doors. Like Steve said, it gets expensive. But I think that it was well worth it. My door panels don't buzz at all and there is less road noise coming in.
For a little less money (I think), there are the aerosol sound dampeners on the market (e.g., Rockford Fosgate). I believe the only problem with them is that the nozzle on those products tend to clog easily.
[This message has been edited by Reg E (edited August 28, 2000).]
