https://www.reuters.com/article/us-tesla-batteryday/teslas-elon-musk-promises-dramatic-cuts-in-electric-car-costs-shares-plunge-idUSKCN26D19P >CEO Elon Musk outlined Tesla Inc's plans to cut electric vehicle battery design and manufacturing costs so radically that a $25,000 car that drives itself will be possible, but the automaker's shares tumbled as Musk forecast the change could take three years or more.