Even if you cold use the front facing camera, you'd then have to ask "which one" as I *think* there are three of them - plus I also think the "picture" they supply is calibrated for the car and not for human vision [1]
In any event, it wouldn't do you any good because they're all at the top of the windshield, so wouldn't give you any reasonable information anyway
[1] then again I could be wrong