Dynomat Question: How many layers?

[Brandon J]

I plan on getting some Dynomat to make my car quieter but I have some questions. How many layers should I get? Also, should I cut out holes wherever holes are in the sheet metal in the doors, or should I cover them up? That's all I plan on doing now - just the doors. Then the rest of the sides later. The audio place I went to didn't have Dynomat - they had another brand. What are the differences between the brands?

Thanks for the help!

[bme107]

Brandon J - see Audio Forum for answer.

Everyone else, keep your replies to the post over there.