Dynamat extreme all the way!
It weighs less than normal dynamat, and works better too!
I have around 7-8 sheets in my car in total, lined the inside of the doors, rear quarter panels, firewall, bit above gearbox, lots of the floorpan, front kickpanels, etc etc etc
Its ace, acts as a heat insulator too.
BUT - Dont fit it on a cold day, it wont stick very well. Get the car warm/hot and keep the dynamay UNROLLED (flat) and inside for a few days first to help soften it up.
Use a narrow wooden roller to help apply it, my roller was designed for decorating the house
about 1.5" wide wooden bit.
Dont try and apply a full sheet either, cut it down into strips/squares and use those... Makes the whole job much easier!
CYa,
Sam C