I've asked this before, maybe nothing ever went there.. but why do they have this slight indentation in the middle at the front opening, as if you could put some kind of container in there, with a liftpoint at the slight indentation (a dip in the sheet metal)... 

I've put stuff there, but its kind of awkward for the hand... to reach in there.. but if could slid in stuff that has to be mailed and deposited into this place, and if the front surface of a tray or container were slanted then maybe it would slide into the rear of the tray, and that way no one could see by looking into the windows, that you have checks or outgoing mail there.. and if you could easily pull out the tray then it wouldnt be so damn frustrating

BTW, I think those map slots are useless, too narrow for fingers, and they can get rained into when you open doors...