America's car makers travelled a rocky road in 2004 with sales for two of the biggest names shifting into reverse gear.

Latest figures released by Autodata, show General Motors' sales down by 1.3%, while the Ford Motor Company fared even worse as sales declined by 4.5% compared with 2003.

An end-of-year advertising and promotions push throughout the industry in December saw a 7.7% increase in the number of vehicles leaving dealers' showrooms versus 2003. And 2004 ended with overall sales of cars and trucks at 16.9 million.

Despite disappointing results for GM and Ford, DaimlerChrysler has reason to celebrate as it sales rose by 3.5%. The other winners are, predictably, Asian marques.

The biggest gains were notched by Japan's Nissan with a 24.1% increase, followed by Toyota's 10.1% rise. The latter also saw sales of its vehicles in the US top two million for the first time. Asian brands accounted for 34.6% of the market, two percent up on 2003.

Says Peter Langlois, analyst at Ernst and Young: "The issue is whether the Asian manufacturers can keep up this surge. It's unlikely that they can match that, just on the sheer fact that they've moved into a lot of segments they weren't in before."

Rising fuel prices have affected sales of some vehicles, especially gas-guzzling SUVs. Ford's Excursion brand dropped by 24%, while Toyota's dual-fuel brand Prius, which can be electrically powered, saw sales rocketing 118%.

Data sourced from USA Today Online; additional content by WARC staff