You can't get everything right the first time around.
Compare the Tesla Model S and the now discontinued Roadster, and the differences are literally night and day. Except for the fact that both are EVs, they really couldn't be any more different. In fact, even Tesla founder and CEO Elon Musk has just admitted that using a Lotus as the basis for the Roadster was a mistake. Musk was speaking at the World Energy Innovation Forum and acknowledged that if Tesla had to do it all over again, they would have built the Roadster from the ground up.
"We ended up changing most of the damn car, so we thought later, why did we do that," Musk stated. What's more, Musk also discussed another issue with the Roadster, specifically regarding its drivetrain. Basically, the overall powertrain wasn't well suited for a commercial vehicle in that it limited both driving range and recharging abilities. But this is how it works with emerging new technologies; it's very much trial and error. Fortunately, it's abundantly clear that Musk and crew have things sorted out now.