How to sound deadening your cab?

I made a new friend up in the north of Sweden. A guy that stumbled upon this webpage when he was out googling for a speedometer kph scale (what a small world), he dropped off a comment here and left his e-mail address and we started exchangeing experience and he sent me a bunch of info about pricing and how to sound deadening a car. So I thaught I could share his work on here ( with his approval):

The truth about Sound deadening

Sound deadening heat test