Elon Musk tweeted a picture of the first production Model 3 sedan Saturday night.FREMONT, Calif. (KGO) -- Elon Musk tweeted a picture of the first production Model 3 sedan Saturday night.Musk posted the tweet just after 9 p.m. He tweeted earlier that "Production unit 1 of Model 3 is now built and going through final checkout."Click here for more stories about Tesla. Report a correction or typo