Not that I doubt their technological prowess, but didn't we have a whole huge batch of fail trying to do the same thing at DARPA last year?

Minus the heavy weapons, a fleet of these vehicles might be useful on the border with Mexico as recon.

They'd just end up stowed in a garage in Vermont, Mark. The Border Patrol not only doesn't patrol the border very well at all, they honestly don't actually want to. Look at how they treated the Minutemen, who performed highly effective intelligence gathering for the BP without even expecting a "thank you" in return. The real purpose of the BP is to prevent US citizens from forming their own organizations to secure the border with Mexico, and to ensure wealthy politicians and landowners never run out of underpaid labor.