U.S. auto sales slowed a bit in December from the brisk pace earlier this year, but automakers still were on track to end 2013 with the best numbers in six years. Chrysler managed a 6 percent gain for December, but General Motors, Toyota and Ford and Volkswagen each posted disappointing numbers. Even so, major automakers reported at least a 7 percent increase for 2013, and analysts expect full-year sales to be up around 8 percent to 15.6 million when all the numbers counted. That would be the highest sales figure since 16.1 million in 2007. “The auto industry was a consistent bright spot in the economic recovery throughout 2013,” said Bill Fay, Toyota division group vice president. “We expect the economy will continue to gain strength in 2014, with car sales rising to pre-recession levels.” However, analysts said manufacturing discounts rose in December, so investors may want to limit their optimism.