Like dinosaurs, ancestors of the tin snail crawl out from a French barn

Like rediscovered dinosaurs from an automotive Lost World, three ancestors of the Citroen Deux Chevaux, mislaid for nearly 60 years, will go on show in Paris today.

The cars, complete with the corrugated bonnets and flimsy deckchair seats are the first pre-production models of one of the great icons of post- war France.

They were built in 1938, 10 years before the cheap, low powered French answer to the Volkswagen Beetle - TPB, Tres Petite Voiture - reached the public. When the Second World War broke out in September 1939, the cars were hidden under bales of straw in a barn near Chartres to prevent the technology falling into enemy hands. (It may seem unlikely that the Wehrmacht would have coveted the Deux Chevaux, but it was classified as top secret at the time).

Three years ago the cars were unearthed, filthy, their bonnets stoved in by the weight of the bales, but intact. They will be the pieces de resistance at Retromobile, a 10-day exhibition of classic French and foreign cars which opens today at the Port de Versailles in Paris.

The Deux Chevaux, also famous, or infamous, for its canvas roof, dashboard gearshift and infuriating folding windows, ceased production in France in 1988 and in Portugal in 1990.

Seven million were produced over 40 years. The original brief of the Citroen designers in 1935 - two years before the first VW Beetle - was to produce a car to convert rural France from the horsecart. More precisely, the intention was to devise a low-price car "capable of transporting two farmers in clogs, 50kg of potatoes or a barrel of wine at 60 kilometres an hour, consuming three litres of petrol for every 100 kilometres". Aesthetic considerations were "of no importance".

The production models of the 2CV exceeded these targets, in terms of petrol consumption at any rate. With care, the car would give well over 50 miles to the gallon, one of the most economical vehicles ever made.

It was, however, never very comfortable at anything more than 50 mph and its death knell was sounded by the building of autoroutes in France from the 1970s onwards. Thousands survive in the French countryside but they are becoming an increasingly rare sight.

No attempt has been made to restore the rediscovered prototypes to working order; they will be displayed just as they were found.

Another 2CV was unearthed, in pieces, at the same farm, close to an old Citroen test track, several years ago. This was a survivor from a small production run, built in 1939. This car was restored and is now running around with its original two-cylinder engine.