NEW YORK -- As Tesla and BYD fight for gains in electric-vehicle sales, Elon Musk's automaker is touting a vision of a self-driving future that will deliver fresh growth.
Unveiling of robotaxi comes amid rising competition with Chinese rival

Tesla shares tumbled on the day after it unveiled its self-driving Cybercab. (Tesla via Reuters)
NEW YORK -- As Tesla and BYD fight for gains in electric-vehicle sales, Elon Musk's automaker is touting a vision of a self-driving future that will deliver fresh growth.