Engineers at Lotus Cars Ltd in Norfolk, England, have been working on aspects of the Tesla electric sports car, due to reach the market before the end of the decade. For many years, of course, automakers have striven to make their cars quieter. Lotus, for one, has developed a noise cancellation technology that actively measures road noise from sensors mounted on the suspension. For sports car drivers, the sound of a large engine is part of the attraction. So Lotus also developed synthetic engine noises that can be piped into the interior, providing simulated sounds of, say, a V8 engine.