I have the interior out of my new-to-me 70 Charger and will be getting one spot in the floor replaced due to rust (driver side, rear seat footwell). The rest of the floors are rock-solid with good factory paint on them. I see a lot of folks with the silver dynamat/noise mat on their floors and I'm considering it, but I'm curious - do they hold any condensation/moisture against the floorboards at all? Or do things stay dry and solid? I had an old '92 Jeep YJ Wrangler soft top years ago, and had the local shop Line-X the interior of that (it made a YUGE difference in noise, and that tub NEVER rusted!), and am actually considering having it done to the Charger (under the carpet, of course)...but if people are having good luck with the dynamat it would likely cost a lot less than the Line-X... The car is going to be garage kept (of course), but as we all know temperature changes make metal sweat and I don't want to cause a problem by adding the mat, if it traps moisture against the metal. Thoughts or experience?