I read a theory on here that the turrets and such are much louder on these modern tanks because the cavernous interiors act as a speaker box, amplifying everything inside. This makes a lot of sense and I have been thinking of putting something to dampen the sound, but being reminded of Flex Seal makes me think this is the perfect way to seal up the switch holes, lessen the axle gap and dampen all vibrations inside the hull. I'm just wondering the mess involved and how many coats would be required since it takes 24-48hrs to dry. Masking might be a challenge too.

I'd stick a spare set of axles in the holes in hopes it would create a sort of built in gasket.