Carlos Sousa of Portugal and Joan Barreda Bort of Spain led the Dakar Rally after Sunday's first stage in Argentina.
Sousa topped the car division, 11 seconds ahead of Orlando Terranova of Argentina and 47 in front of Nasser Al-Attiyah of Qatar.
Two of the pre-race favorites were just behind - Carlos Sainz of Spain was in fifth place and 11-time champion Stephane Peterhansel of France was sixth.
In motorcycles, Barreda Bort was 37 seconds ahead of fellow Spaniard Marc Coma and 1:40 in front of defending bike champion Cyril Despres of France.
The two-week rally, with more than 400 entered, will wind through Argentina into Bolivia, and then head south to the finish in Valparaiso, Chile.
Monday's second leg goes from San Luis to San Rafael, before it begins to head north for the third stage.
The rally, being run for the sixth straight year in South America, could draw protests in Bolivia. Aymara Indians fear the stages across the world's largest salt flat will damage the environment, with crowds leaving rubbish and racers leaving behind deep creases.
The Aymara have vowed to block the Jan. 12-13 legs of the rally. However, the event has received the support of President Evo Morales, who is an Aymara.
The Salar de Uyuni is 11,800 feet (3,600 meters) above sea level and stretches over more than 4,000 square miles (11,000 square kilometers). It's a breeding ground every November for South American flamingos, and the briny water under the lake's hard surface has high concentrations of lithium, which is mined for batteries.
Environmentalists in Chile have also opposed the event, saying it endangers archaeological sites.
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