A Mercedes-Benz CLA EV prototype toppled a record set by the Porsche Taycan Mercedes drove a CLA EV 2,309 miles in 24 hours around the Nardo test track The Mercedes CLA EV could become the most efficient EV on sale in the U.S. Records are meant to be broken, and Mercedes-Benz has just busted one set by Porsche. In April, Mercedes-Benz quietly took…