AP, DETROIT, MichiganRecord sales of electric vehicles in the fourth quarter helped to push Tesla Inc to its second-straight quarterly profit, giving bullish investors optimism that sustained profits are ahead. Tesla expects to “comfortably” exceed production of 500,000 vehicles this year at its factories in Fremont and Shanghai, with Model Y production in Shanghai to start next year. However, the company still has a long way to go before its vehicles can travel without humans taking the wheel. Tesla expects net profits going forward, with some possible exceptions at times surrounding the launch of new products. Tesla continued to build its cash balance during the fourth quarter, reporting US$6.27 billion available, up from US$5.34 billion at the end of the third quarter.