Dynamat Install

I want to install Dynamat on my entire car. How many sq feet are we talking about and how much money am I looking at?

just my opinion, you may want to try this company www.b-queit.com They are less expensive and works as well as dynamat. Not sure how much you'll need to do your whole car but I used almost 140sq feet double layer in the trunk, spare tire well, cd changer well, doors and door panels, trunk panels, behind the sail panels, and dash.

how much weight are we talking about and how much speed am I going to lose?

Don't buy Dynamat. One of the most overpriced products around.
http://www.termpro.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=40;t=008863
I have RamMat. Works well.

If you are worried about price and weight.... I would just seek out the parts that are rattling and wedge something in there to prevent the vibration. You know, I've had better results doing that then layering the whole car in dynamat. Unless you are going for SPL...... or putting it directly behind your speakers... to improve SQ......