MAR DEL PLATA: Argentina. A colourful cavalcade of cars, motorbikes, quads and trucks set off from this Atlantic resort Sunday for the 33rd edition of the mythic Dakar Rally.

The 2012 Dakar promises to be as tough as any in the event's drama-laden history, tracing a route across the South American continent, over the Andes and through the Atacama desert to the Pacific coast in the Peruvian capital of Lima.

Heading the list of 466 intrepid adventurers are Nasser al-Attiyah, the Qatari driver crowned champion in 2011 after the heartache of disqualification in 2009 and missing out on victory to Carlos Sainz in 2010.

Attiyah, who is hoping to compete for his country in shooting in his third Olympic Games in London, was almost facing the prospect of missing a defence of his hard earned title when Volkswagen pulled the plug on their Dakar involvement.

But the versatile 41-year-old has found a new home driving a Hummer for Team Robby Gordon.

"The thought of not doing the Dakar almost made me sick but things eventually turned around," he said.

"It's fantastic because it's a new challenge for me and I'm proud of being able to represent Qatar," added Attiyah who is seeking to emulate Ari Vatanen (1990-1991/Peugeot-Citroen) by winning back to back Dakars in different cars.

Hummer's best performance so far was third place in 2009.

Unlike Attiyah, Sainz was unable to find a replacement drive following Volkswagen's decision not to compete but one name that jumps out among his rivals is Stephan Peterhansel.

The French master holds the record of nine Dakar victories, six on a bike and three in cars, the last coming in 2007.

Attiyah is also up against South African Giniel De Villiers, who will be out for revenge after coming off second best in 2011.

Marc Coma, the reigning Dakar bike champion, is back to defend his crown and aim for what would be a fourth title after his previous wins in 2006 and 2009.

The Spaniard's main rival once again is France's three-time former champion Cyril Despres.

At 71 years of age France's Claudio Regunaschi is the oldest competitor in this year's edition, with 20-year-old Argentine bike rider Lucas Bonetto the youngest.

In keeping with the Indiana Jones-style spirit in which this iconic race is steeped amateurs make up 80 percent of the 2012 Dakar competitors' list.

This is the fourth time the Dakar has been staged on the continent since being uprooted from its habitual African habitat due to security concerns.

The 2012 route comprises five stages in Argentina, five in Chile where Attiyah and company face the daunting Atacama desert and four in Peru, finishing in Lima after 4,200 kilometres of special stages on January 15.

The hardest day's racing awaiting the assorted collection of cars, bikes, quads and trucks is arguably the daunting 276km 12th stage, from Nasca to Pisco in Peru.

"From the time the rally enters Chile to its arrival in Lima we have 7-8 stages of pure desert, sand, dunes, with the stages in Peru promising to be exceptional," said race director Etienne Lavigne.