General Motors launches GM Marketplace in a bid for customers\u2019 habits. Simon Erickson returns from Texas to analyze GM\u2019s newest venture, as well as Starbucks\u2019 brand new (massive) roastery in Shanghai. Plus, we dip into the Fool Mailbag and share 3 stocks we rarely discuss. MarketFoolery\u2019s holiday music festival continues with some help from Harry Connick, Jr!