quick question about protecting the diffs

[cdog4w]

I wanted to cover the holes in the chassis in order to protect the diffs. I assume the holes are there because the diffs extend into the chassis - so the holes were cut to accomodate them. My plan was to take a little square of lexan (leftover from the packaging) and super glue it over the hole in the front and back. This would still allow the diff the same amount of space but cover the hole and prevent grit and other debris from getting into the gears. Is there another reason for that hole to be there (ie. a reason not to cover it) or will I be ok superglueing the covers on? Thanks.