Yahoo Finance's Editor-In-Chief Andy Serwer recently took a road trip in a Tesla to test out the company's ecosystem, including planning out your route to match the supercharger locations. Tesla also announced that it's bringing back the program that provides free, unlimited access to superchargers for all new Model S sedans and Model X SUVs. While Musk once called the program "unsustainable," it's an appealing incentive for customers looking into buying one of the pricey vehicles.