Mexico light-vehicle sales tumbled 19.9 percent in December, the steepest monthly fall of the year, to 101,258 cars and trucks.
For all of 2008, Mexico's sales dropped 6.8 percent to 1,025,449 from 1,099,878 in 2007.
Cars outsold trucks in 2008. But trucks gained market share, with sales dropping only 4.9 percent to 439,758, while car sales fell 8.1 percent to 585,691.
General Motors edged Nissan Motor Co. to retain the annual sales title, after a year when the two automakers seesawed in the standings.
GM sold 212,378 units, a 7.8 percent drop from 2007. Nissan sales fell 1.0 percent to 212,022 units.
Volkswagen finished third, as it did in 2007, with 137,722 sales, down 10.5 percent. Ford Motor Co. followed, slipping 15.7 percent to 132,071. Chrysler LLC rounded out the top five with 116,137, a 9.6 percent fall.
GM held onto the 2008 top spot despite a 23.2 percent tumble in December to 20,409. Nissan's December sales fell 20.4 percent to 20,008.
Among other automakers in December, Volkswagen slipped 8.9 percent to 15,068 units. Ford sold 13,160 in December, a 13.2 percent decrease. Chrysler fell 42.0 percent to 9,459.
Honda, Ferrari, Isuzu, Mazda, Subaru and Suzuki all had higher sales in 2008. Of these, Honda Motor Co. sold the most vehicles — 56,264, a 2.7 percent increase.
Import vehicle sales bore the brunt of the slide, falling 28.3 percent in December and 12.5 percent for the year.
Sales of domestic vehicles, which made up 40.5 percent of the market in 2008, slipped 5.0 percent in December but grew 3.2 percent for the year.