Through the 1950s and 1960s, a horde of little cars competed at Le Mans for the Thermal Efficiency Index prize. The idea of this formula was to reward those who tried for performance without using oceans of fuel and the competing cars were invariably small, ultra-streamlined and powered by tiny engines. I have always felt that the drivers of these little wonders must have been very brave to head down the Mulsanne straight at their maximum 120 mph or so with the big cars screaming past at close to 200 mph.

A consistent entrant and winner of the class was the small French firm, D.B. - the initials indicating the partnership between two designers, Charles Deutsch and René Bonnet. When the pair split up in 1962, Bonnet started building cars under his own name with Renault supplying the engines.

And so was born one of the prettiest little GT cars ever - the René Bonnet Djet. It was one of the first production mid-engined cars and, thanks to its light weight, was as zippy as it looked. With only one liter of engine, it still managed a top speed of about 110 mph. Most were bought for racing in spite of being intended for road use.

By 1965 M. Bonnet was in financial difficulties and sold out to Matra, who continued production of the Djet and eventually rebodied it with one of the ugliest designs ever. As a result, the original Bonnet Djets are still regarded as the real thing.

Here’s a strange one - the Tatra 603. Made in Czechoslovakia, the 603 was actually well before its time when first designed in the fifties. The company has been going strong for almost as long as Benz, although they gave up making cars in the nineties, preferring to concentrate on their successful truck range.

But Tatra began its tradition of rear-engined vehicles in the thirties, even Dr Ferdinand Porsche “borrowing” heavily from Tatra designs in the design of his Volkswagen. The 603 was one of these rear-engined curiosities.

But the uniqueness of the 603 does not end with its unusual positioning of the power plant. The engine was an air-cooled 2.5 liter V8! Okay, it only produced 95 bhp but imagine all that weight swinging around behind the back axle. The handling was spectacular at speed as a result - but it did not matter too much since only the top party officials and factory managers could afford to have one. They were interested in luxury rather than performance and the 603 delivered in that area.

Those Czechs know how to put together a good car, in spite of the undeserved reputation of the old Skodas, and Tatra was no exception. The company holds a number of impressive records, as well as Dr Porsche’s respect - it is the third oldest car manufacturer in the world and was the first to introduce a body influenced by aerodynamics.

Further to my previous post on the Auto Union D-Type, I see that Christie’s are now saying that they expect the D-Type to fetch in the region of $12,000,000. There is an inaccuracy in CNNMoney’s article on the car that I ought to correct, however.

It is not quite true to say that Auto Union are now known as Audi. Auto Union were exactly what their name states, an amalgamation of several German manufacturers, one of which was known as Audi. In the sixties, Auto Union was absorbed into Volkswagen but was allowed to disappear, apparently forever.

In the seventies, when VW decided that they needed a new marque to make luxury cars and to dissociate it from the company’s “beetle” image, someone obviously remembered that they held the rights to the Audi name and it was duly resurrected. It can hardly be said that Audis are the descendant of the D-Type, therefore - only the Audi name survived.

But I don’t suppose VAG will mind at all if their cars are associated in some way with the D-Type - it was a glorious beast, after all. Just take a look at this…