(Reuters) – Electric carmaker Tesla Motors Inc TSLA.O said on Friday it had boosted warranty coverage on its Model S sedan, a week after an influential U.S. consumer magazine highlighted problems with the $70,000-plus vehicle. Tesla announced that the drive unit warranty on the Model S has been increased to match that of the battery pack, bringing its coverage to eight years and “infinite” miles. The warranty extension will apply retroactively to all Model S […]