i'm in the middle of restoring my 90 CRX Si and after taking the sound deadening out there are holes in the floor with caps and sealed shut

i don't have "rust" holes, but these are holes from the factory and then capped, and sealed with seam sealer

this isn't my car, but just one i found online for reference

http://image.superstreetonline.com/f...rear_plate.jpg

to the left of the rollbar mount, that hole


So my question of the day is, what is the point of these holes being there? and if i were to take the caps/plugs out and weld in a coverplate, what would be the drawbacks?

 

just there for production, when they dip the car in solvent before paint so it drains out, then capped over and painted.