Here's a shocker in more ways than one. Earlier this month, Enterprise Rent-A-Car announced that it would soon be offering Chevrolet's Volt at the company's Mark Christopher Auto Center in Ontario, California, and we reasonably assumed that renters best watch out for any unforeseen charges that may arise from returning it with a dead (or near-dead) stash of batteries. For anyone who has rented a gasoline-powered automobile in the past score, you'll know t