door vents?

[personaltrainer]

wondering how essential the vents on the lower door panels are. I'm gonna be building new ones with new speakers etc and would like them to be as solid as possible but not if it means the door will rot off or something. Anyone else covered these up? can't imagine it would be a big deal?
thanks.

 

[spearchucker]

The only thing I can think of is that if you don't have them then you might end up having positive pressure built up when you use the AC or heater and they won't work as efficiently.