Hello Mike. First, thank you... but there are a bunch of more interesting threads here. Mine it's just too long and boring :mrgreen:
About insulation: welll, both! Dynamat is mostly for sound but there are some other Dynamat materials for heat insulation and I'm still ponder buying them or not. However, the aluminium layer has plastic air bubles in the interior and it's for heat insulation. The last one, works well both ways.
I can tell you that knocking on the outside of the panels where I applied Dynamat, the sound and felling is like knocking on a piece of wood.