I've seen them. They're usually standard issue mailboxes, but painted like the winged helmet.
Edit: I didn't mean to sound like a dick there... I just mean that the ones I've seen were hand painted.
Maybe I make an decal with MS Paint?
...road forks you!
I'm jealous. Hard to say with the switch-back/over right now, but check the M-Den and Moe's type places. Or U-M/Den catalog when it's back to normal.
... you need strong Google skillz in 2010 (I used "college mailboxes"); I have seen these in the wild and they look like crap IMHO:
http://www.sidelinemvp.com/ncaa-mailbox.html
http://www.jandjsweb.com/product_details.em?product_id=350722
http://www.redelephants.com/acatalog/Collegiate_Mailboxes.html
Those Google skillz are mad fo' sho'!
It's crap, but your Google skills are top bollocks!
http://www.dayoopers.com/the.store?page=catlg14a.html
EDIT- I just realized it's just the magnetic cover.