Four celebrity duos put their driving skills and relationships to the test as they join in on a part of the Endurance Rally Association's Road to Saigon in a fleet of classic cars.From Chiang Mai in Northern Thailand through Cambodia and Vietnam their challenge is to drive over 3000 km, through some of the least explored areas of the region and taking on some of most challenging roads in the world. Over 12 days the BBC series captures all the laughs, beautiful landscapes and inevitable drama of this truly unique journey revealing if the celebrity ralliers have got what it takes to make it all the way to the finish line.To be in with a chance of getting to the finishing line, they have to work closely in their driver/navigator pairs finding their way using a Tulip Map and try to keep their cool when engines fail and cars break down. The ralliers will also have a chance to soak up the sights and sounds of this part of the Far East and reflect on its recent past.This once in a lifetime experience tests the teams, and their cars, to the limit.