I've seen Booster Fuels trucks around at a company I used to work at. To me this makes the most sense as a perk offered by a company not in a major city, that has huge parking lots of cars. I used to commute to Santa Clara 3x a week from SF and needed to re-fuel every week. If the company offered the service as a perk with me just paying for gas, that would be pretty convenient no-brainer.