My car doesn't have any insulation in the tunnel at all, not sure if that's a GT500 thing or something they added in the later models since mine's an 05 but I definitely don't have any. Nice shop by the way!
My 2005 didn't have insulation, but during my transmission rebuild I put dynamat in the trans tunnel and it is holding up fine. It did melt a little bit where I had it too close to the exhaust though.