I stripped out all of the old sound deadening material from my R32 GT-R in prep for replacement. In doing so, the rubber grommets / plugs / covers (take your pick of name) in the floor were removed. Most were either somewhat perished, had shrunk or were destroyed by removing the sound deadening. I have bought all of the replacement parts. I have had a bit of a search and looked through the workshop manual but have not been able to identify:
What product should be used to seal the plugs? I am not fussed about using the original product (would prefer not to) but what would be suitable sealant to use now? Some were sealed in using something akin to the seam sealant but this required a combination of dry ice and a hammer to remove.
Which plugs should be sealed? Obviously those that cover bolts that need to be removed for maintenance shouldn't be sealed. Also some that I would have thought shouldn't be sealed were or randomly / partially sealed. E.g. 74300AA / 06212-5500P in the spare wheel compartment was sealed when I thought that was supposed to be able to serve as a drain if required (R33 Boot - Water Leak)
Pictures from Nissan FAST for reference showing the plugs in question: