In the article he's quoted as saying:
“Corporations are imaginary entities, and we’ve let them run wild,” Friedman has stated, according to a San Jose Mercury News article. “Their original intent…was to serve human beings. So I’m wresting back that power by making their personhood serve me.”
So, I don't think he actually buys his own argument. It seems more like a stunt, or trying to prove a point.
...considering his corporate papers can't drive, and the point of carpooling is to use less cars, I don't think they should give him a pass in the carpool lane. XD Otherwise his papers should just take the bus. :p