Ford ( F) had a chance to put its best foot forward at the Detroit auto show in December, but now the struggling automaker has to show investors the full monty. It's not going to be pretty. Shares of the No. 2 U.S. auto manufacturer have climbed nearly 5% since the beginning of December. But when Ford reports its fourth-quarter results Thursday, it's expected to show huge losses for a period when sales cratered, and some analysts say the stock will give back its gains. To be sure, much of the negativity is priced into shares of Ford at this point. And new CEO Alan Mulally is enjoying a grace period with analysts as he gets his bearings in his new post. But observers say Ford probably doesn't have much more to show investors in the way of cost cuts, and its sales are headed for further weakness as the economy potentially slows in 2007. "In its weakened position, Ford is very vulnerable to any wear and tear that might show up in the economy later this year," says Erich Merkle, an analyst with the auto consulting firm IRN. "We're forecasting a consumer slowdown in terms of vehicle demand, and Ford's sales results going forward may be especially unnerving to people because it could show double-digit declines."