Audi revives the Auto Union Lucca, born for war with Mercedes

On a stretch of the Florence-Viareggio autostrada outside the Tuscan city of Lucca, on the morning of February 15, 1935, a silver projectile shaped like nothing the automotive world had seen before accelerated through the Italian winter light.

Hans Stuck, a veteran racing driver, pressed the car to 326.975km/h (203.173mph).

The official timekeepers, using electrically triggered photocells, recorded the passing as something close to a blur.

The car set a widely acclaimed flying-start mile record and, according to Audi’s historical material, ultimately broke 26 world records and 13 international class records. The car’s handlers immediately declared it the fastest road racing car in the world.

Ninety-one years later, almost to the month, Audi Tradition has unveiled a full recreation of that machine — the Auto Union Lucca — in the same Italian city where it made history.

The timing is deliberate, and so is the choice of restorer. Crosthwaite & Gardiner, the British specialists who have spent more than three years on the project, built every component by hand, working from historical photographs and archival documents.

The result, completed in early 2026 and now destined for Audi‘s historic vehicle collection, carries a drag coefficient of 0.43 — measured in Audi’s own wind tunnel at the end of April — and will make its first dynamic public appearance at the Goodwood Festival of Speed in July.

The car is extremely peculiar even for current standards: Low and tapering, with a fin-like rear end, teardrop-shaped wheel arch covers, exhaust pipes grouped upward into twin outlets on each side, and a sealed cockpit of clear-lacquered light alloy.

When the contemporary press coined the term Rennlimousine – racing saloon – for it, they were reaching for a category that didn’t quite exist. It was a highly unusual closed-body racing machine for its time.

The Star versus the Four Rings

To understand why Auto Union was racing across European autobahns in the depths of winter, trying to shave fractions of a second from a flying-start mile, you have to understand what speed meant in Germany in the 1930s.

It was not merely an engineering objective, but a propaganda instrument, a measure of national vitality, and for two rival companies whose cars happened to have been stripped of their coloured paint and finished in bare aluminium silver, an obsession that consumed engineers, drivers, and an enormous public audience.

Auto Union had been formed in 1932 by the merger of Audi, DKW, Horch, and Wanderer, the four rings of its badge representing the four constituent brands. Ferdinand Porsche designed its Grand Prix car: a mid-engined, supercharged machine, radical in concept at a time when every serious racing car placed its engine ahead of the driver.

Under the 750kg formula that governed Grand Prix racing from 1934, Auto Union entered with the Type A, producing 295 horsepower from a supercharged 4.4-litre 16-cylinder engine mounted behind the driver’s seat.

Daimler-Benz entered with the W25, a more conventional front-engined car but one developed with equivalent ambition.

The two German manufacturers would dominate European Grand Prix racing for the rest of the decade, and the competition between them was fierce enough to function almost as a second rivalry running inside every race.

The speed record battles were, if anything, even more naked in their competitive intent.

On 6 March 1934, Stuck set three world records in the Type A on the Avus circuit in Berlin. On 20 October, he added five more.

The records spanned a range of distances and durations, and each one was a news event.

Daimler-Benz could not allow them to stand. Rudolf Caracciola, its number one driver, took a specially constructed Mercedes to the highway near Gyón in Hungary in late October 1934 and set a series of international class records of his own. Among them: a flying-start mile averaged at 316.592 km/h (196.721mph). That was the number Auto Union had to beat.

Hungary to Milan to Tuscany

The engineering response at Auto Union’s racing division in Zwickau came quickly.

Working from the car that had set Stuck’s October records, the team built a wind tunnel model and tested it at the Aeronautical Research Institute in Berlin-Adlershof, an early application of aeronautical science to a racing car that contemporary press described as a first in European motor sport.

Tests were conducted on both open and closed-cockpit versions. The closed version won. By December 1934, the car was finished. Stuck drove it at Avus on 17 December.

The original plan was to return to Hungary, to the same road near Gyón where Caracciola had set the record they were chasing. Arrangements were made with the Royal Hungarian Automobile Club and the car was transported to Budapest.

On 5 February, the team drove to the route, but the weather turned. Two test runs were managed before an exhaust pipe burned through, and with deteriorating conditions and an unreliable forecast, the decision was made to move.

The team headed south toward Milan. The road near Bergamo proved unsuitable. They kept going south again, deeper into the Italian winter, searching for five kilometres of level, straight, high-grip autostrada.

They found it between Pescia and Altopascio, on the Florence-Viareggio road, near Lucca. The stretch was ideal: eight metres wide, essentially straight, grippy. Test runs began on the afternoon of 14 February. The team adjusted the radiator grille, dialled in the wheel covers, and analysed the data.

On the morning of the 15th, with Stuck at the wheel and official chronometrists in position, the front of the radiator was almost entirely sealed and the car made its attempts.

The Automobilrevue reported thousands of spectators watching, and prominent figures from the Italian sporting world who had made the journey specifically for the occasion.

Stuck covered the flying-start mile at an average of 320.267km/h across two runs, and during one return run his car was timed at 326.975km/h over a single kilometre – 11.01 seconds of flat-out driving. The record was set.

The timing, in Auto Union’s telling, was almost theatrical: an identical version of the car had been displayed the previous day at the International Motor Show in Berlin, alongside a promotional poster listing every world and class record the four-ring brands had ever set.

The young man on the front row

The Lucca car’s next appearance came three months later, at the fifth International Avus Race in Berlin on 26 May 1935. Because Avus was a non-formula event – no 750-kilogram limit – Auto Union entered not just two Grand Prix cars for Stuck and Italian ace Achille Varzi, but both Rennlimousinen as well.

The Berlin motor show car, fitted with a slightly larger radiator grille for circuit use, was numbered four. Its driver was a 25-year-old who had signed with Auto Union for the 1935 season and had, to that point, not completed a single circuit race.

Bernd Rosemeyer had come to racing via motorcycles, and specifically via the kind of fearless, instinctive riding that transfers imperfectly to four wheels unless you happen to be built for it. He was.

In practice at the Avus, he reached 290km/h in the Rennlimousine, quick enough to earn a place on the front row alongside Stuck.

In the first heat, accelerating out of the north curve, his right rear tyre burst. Rosemeyer kept the car off the barriers and rolled to a stop. His first circuit race for Auto Union was over in seconds. The Lucca car, driven by Prince Hermann zu Leiningen in the second heat, retired with a damaged coolant line.

Neither finished, but Auto Union had found in Rosemeyer something rarer than straight pace: a driver who seemed to find the Porsche-designed mid-engined car’s famously treacherous handling not terrifying but interesting.

Where others described the Type B and Type C as near-undriveable under power – the engine behind the driver creating snap oversteer that few had the reflexes to catch – Rosemeyer drove them as if the instability were simply part of the technique.

By 1936, he was European champion. By 1937, he was the most celebrated racing driver on the continent.

The logic of the streamliner

The Lucca car’s aerodynamic thinking did not remain static. The lessons from Berlin-Adlershof and from the Tuscan record runs fed back into the racing division’s development work, informing a more radical project that would reach its conclusion in 1937.

Josef Mickl, the aerodynamicist who had worked with Porsche, designed a new body over the chassis of the Type C Grand Prix car, lower than the Lucca car, smoother, more completely enclosed, the wheel arches faired in and the cockpit canopied beneath a teardrop form.

The engine was the six-litre Type C 16-cylinder, producing around 560 horsepower. The car became known simply as the Streamliner – Stromlinie in German – and it was, by the standards of its time, extraordinary.

Rosemeyer drove it to 406km/h (252mph) on the Frankfurt-Darmstadt autobahn in October 1937, setting a new absolute land speed record.

Mercedes-Benz responded in January 1938, Caracciola taking a specially built W125 record car to 432km/h (268mph) on the same road.

The rivalry that had produced the Lucca record in February 1935 had now escalated into something with no natural ceiling.

Rosemeyer went out the same day to reclaim the record. He was doing in excess of 440km/h (273mph) when a crosswind caught the Streamliner on an exposed section of the autobahn, broke its traction, and sent it spinning off the road. He was killed instantly. He was 28 years old. His wife, the celebrated aviator Elly Beinhorn, had watched from the roadside.

The event brought the land speed record attempts on public roads to an effective end. No comparable run was attempted in Europe for decades.

Bringing it back

What Audi Tradition has done in rebuilding the Lucca car is to recover a machine that sits at the hinge of all of this history.

The Rennlimousine is not the Streamliner – it is earthier, more improvised, the product of a frantic winter development period and a team moving across three countries in search of suitable road. But it is the direct ancestor: the car in which the aerodynamic logic that would eventually take Rosemeyer to 440km/h was first properly realised at speed.

The Streamliner’s enclosed cockpit, its faired wheels, its low drag profile – these ideas are all legible in the Lucca car three years earlier.

The project manager for the recreation, Timo Witt, has spoken about the degree of improvisation required even in building the replica.

“I’m impressed by the agility and speed with which they responded to the competition back then – in the technical realm, in vehicle development, and in organisational matters: when the weather takes a turn, the whole team moves on without hesitation,” Witt said.

“Of course, we recreated the car as authentically as possible, but at the same time, issues such as the car’s durability and maximising efficiency in the project’s implementation were also important to us.”

The car that will appear at Goodwood in July is fitted with the Type C’s six-litre 16-cylinder rather than the five-litre unit of the original record car, because visually the two are indistinguishable and the larger engine allows it to run within the Silver Arrow family for demonstration purposes.

Several of the modifications made to the Lucca car for the Avus race in May 1935 have also been incorporated, primarily to manage thermal stress during running.

The replica is, in other words, a considered approximation – as close to the original as practical judgement allows – rather than a frozen historical artefact.

That feels appropriate. The Lucca car itself was an approximation: a record attempt machine built under time pressure, driven across a continent in search of weather, adjusted at the roadside on the morning of its greatest run.