The biggest car dealership groups swallowed a bigger share of U.S. auto sales last year.
New-vehicle retail sales for the top 125 dealership groups grew a collective 19 percent in 2012, while the whole U.S. market rose 13 percent. Tallying just the 113 dealership groups that were on the list for both 2012 and 2011, new-vehicle retail sales were up 18 percent.