If I could work in my car, I could also work at home, and more effectively. I think it more likely that I would rest or entertain myself in my car, and work when I get to work.

As cool as it may sound to be able to work in your car during your commute, it's even cooler to work from home and have no commute at all. If my corporate overlords won't countenance the latter, they almost certainly won't allow the former.