Tesla Inc. reported a surprise increase in quarterly vehicle sales as US consumers accelerated electric-car purchases before federal tax credits expired.The company delivered a record 497,099 vehicles worldwide during the period, up 7.4 per cent from a year ago. That compares with the roughly 439,600 average projection compiled by Bloomberg.Tesla has sought to revive its core automotive business, which languished for several quarters under the weight of an aging lineup, rising competition and the eliminatio ...