I'm planning to sound deaden my car doors but I notice that dynamat sells 10" by 10" sheets, as well as full door sheets. Obviously there is a significant price difference between the two. Is just getting the 10x10 for the woofers good enough? Also should I bother putting some behind the tweeter, is it necessary for high frequency waves? I doubt very much that the entire door sheets are needed, but is there other sections in the door that are prone to rattling that should be sound deadened?
Perhaps useful info: My components will each be receiving 150 watts, and for a while until I can afford my sub they will be covering 50+Hz.

 

Ideally, you will want to do the entire door (outer panel, inner panel back and front) if possible. If you don't have the budget right now, then the "speaker kit" package will do until you can. And yes, it usually will make a difference. I suggest purchasing a decent amount of deadening product if you're fairly serious about sound.
The tweeter does not really need deadening by itself. The whole idea/premise is to mass load the surface/panels, so it's the mid that will resonate/vibrate the door panel more.
Do a search, there's lots of good info to be found.

 

roll the window up and clean off the inner skin of the door with a good solvent. then line it as well as you can... then try to get as much on the back side of the outer skin, this is really trickey as the window regulater and other things are in the way plus your arm dosent have a joint half way up the radius or ulnar, then line the outside of the door completley, finally line the actual door panel itself with some.... lots of work but will make your door bullet proof.... good luck.. go to photobucket and look at my 03 civic for an idea of what it should look like.