Enterprise Rent-a-Car is zooming ahead with a car-sharing program à la the successful Zipcar. The Enterprise venture, called WeCar, started on the campus of St. Louis’s Washington University last month, but will kick off in urban style in the city downtown next week. WeCar will begin with nine Toyota Prius hybrids and will target employees who commute without a car to work and then need a vehicle during the day. (Zipcar, which targets residential areas, is not available in St. Louis.) WeCar joins a U-Haul program with the self-explanatory name U Car Share, available in college cities like Ann Arbor, Mich., and Berkeley, Calif. Car rental companies Hertz and Avis are also eyeing car-sharing. Because, as we all learned in kindergarten, sharing is caring.