Dynamat & factory insulation
I chose to use the factory insulation on the firewall for a couple of reasons:
a) I had it.
b) The push pins used to hold it to the firewall plug the holes.
c) I didn't want to see silver foil when I look under the dash.
d) I wasn't worried about eliminating as much noise or heat as possible.
I ran the RAAMmat up the toe board to just below the heater box. Carpet hides it. Factory isulation takes over from there.