Reuters: Electric car start-up Tesla Motors Inc on Wednesday said it should be profitable by the middle of this year and that it sold out of its Roadster sports car model until early November. Founder and Chief Executive Elon Musk, in a company newsletter, also said the company expects to receive funds from a $350 million Department of Energy loan within four to five months that will go toward a new four-door electric sedan set to go into production in 2011. “The Obama administration …