Tesla’s Troubles Raise Questions About Its Invincibility

Elon Musk appeared to be in a defiant mood Wednesday when he stood before employees at Tesla’s factory near Berlin a week after an arsonist set fire to a high-voltage power pylon and brought production to a standstill. “They can’t stop us,” Mr. Musk, the company’s chief executive, told workers in a giant tent beside the plant. But there are proliferating signs that Tesla may not be as unstoppable as it once seemed. The company’s car sales are no longer growing at a torrid pace. Chinese automakers and established brands…