“ The Week that Electric Vehicles Went Mainstream ,” is how Tesla Motors headlined its blog post last week, citing more than 325,000 pre-bookings for the Model 3 electric car it launched on March 31. “[That] corresponds to about  billion in implied future sales, making this the single biggest one-week launch of any product ever,” the company boasted. Deliveries are set to begin in 2017. Tesla may well be on the way to mainstreaming the electric vehicle market for itself and its competitors. In addition to the wide appeal the Model 3 seems to command, several other aspects point to a potential journey away from a niche market for Tesla. The car’s $35,000 price tag is half the price of the Model S ($75,000) and the Model X ($80,000). Bookings for the Model 3 have surprised even Tesla’s founder and CEO Elon Musk , coming at a time when gasoline prices are low.…