The Most Devastating Engineering Miscue Found in Early A-Bodies

I'm thinking of modifying mine to be removable.
63-67 Corvettes had two rectangular cowl vents that were about 4"x10" each, and they were held in with philips head screws. Easy out; easy in. If I do another A body, I am definitely going to replicate that idea. Done properly, it would be seamless and quite functional.