Tesla Inc. workers at its only auto plant have contacted the United Auto Workers seeking assistance with forming a union, according to a Medium post published Thursday by a man claiming to be a factory employee. “I think our management team would agree that our plant doesn’t function as well as it could, but until now they’ve underestimated the value of listening to employees,” wrote Jose Moran, who identifies himself as a worker for the past four years at the plant in Fremont, California.