We know about the not-using-the-Lotus thing because the Tesla Motors CEO said as much yesterday at the World Energy Innovation Forum at the Tesla Factory in Fremont. The two-day event, which also offers Model S test rides and a factory tour for attendees, featured a fireside chat with the electric automaker's CEO and Ira Ehrenpreis. During the discussion, Musk revealed that if he had to do it over again, he would have built the Roadster from the ground up instead of using the Lotus Elise chassis. "We ended up changing most of the damn car, so we thought later, why did we do that," he said.
"We ended up changing most of the damn car" – Elon Musk
Another problem with the original idea for the car was the drivetrain. At first, Tesla had meant to use the motor and other propulsive bits from AC Propulsion, only to find that powertrain didn't work well in a commercial application. Instead Tesla only licensed the reductive charging patent, which allowed some integration of the inverter and charger.
Besides knocking Tesla's own early efforts, the outspoken entrepreneur took a couple swings at other technologies with quotable quotes such as: "The internal combustion engine is a ridiculous thing!" and "Current lithium ion technology is better than theoretical fuel cell limits. So, game over. Why bother with fuel cells?" Looks like there are some things Musk is not interested in going back in time and changing.