Sleeker, lighter, faster – a sports roadster is pure hedonism, a machine whose joy in being punted down a road sums up its raison d’être. 90 years ago, an open-top sports car arrived on the scene to give the small but tough BMW 3/15 a little company. The newcomer soon got into racing, putting the cat among the pigeons in its class. And it wasn’t long before a whole generation of car lovers were dreaming of one on their driveway.

Having enjoyed considerable early success with its high-tech motorcycles, BMW extended its focus to four wheels in the late 1920s. Capacity was expanded with the acquisition of the DIXI car factory in Eisenach, which had cutting-edge machinery but also serious debts. The small car built under license at the plant – in effect an Austin Seven – was brimful of natty details and still very much fit for purpose, but not exactly a spring chicken. The BMW technicians and engineers promptly set about whisking it into the future.

Small car, good timing.

Cue the arrival in July 1929 of the BMW 3/15 PS Type DA 2, fronted by a fresh radiator and change of name. However, these relatively trifling tweaks were overshadowed by a raft of major upgrades. The body was now wider and the running boards were dispensed with. The result was more space inside: “Bigger inside than out!” screamed the ads. Far more powerful brakes acting on all four wheels and comfort enhancements like wind-up windows sweetened the deal.

Further additions were made to the model range in 1930. In addition to the state-of-the-art, steel-bodied sedan and coupé, customers were able to choose from two- and four-seater convertibles – in relatively simple tourer guise or super-luxury spec. And there was also a delivery van for businesses. The Wartburg (Type DA 3), however, was the main event.

The stuff of dreams for the sporting at heart.

Here, then, was an athletic two-seater with a tapering boat-type tail (all the rage at the time), an alloy body, a folding and shatterproof windscreen, extra engine power (18 hp, up from 15 hp), Bosch shock absorbers and a drop-centre front axle giving a lower centre of gravity. The whole thing weighed just 410 kilograms. And with a top speed of 85 km/h (53 mph), it was a full 10 km/h (6 mph) quicker than its more measured siblings.

This was a sports roadster with a permanent smile on its face, and the little BMW soon tasted great success in the popular car races of the time. It was the hot favourite for class victory on any grid it graced and did much to cement the brand’s reputation for dynamic ability. BMW had grand plans, and unbridled driving pleasure was part of them from the outset.

The BMW 3/15 Wartburg was not a massive seller; it was just too specialised and, in an era of widespread unemployment, a distant and unaffordable dream for too many potential customers. It retailed at 3,100 reichsmarks, a princely 925-mark premium over the lowest-priced BMW 3/15. Ultimately, only 150 examples found homes, a tiny number alongside the over 25,000 units of the DIXI and BMW 3/15 sold. No wonder this remains one of those rarest and most coveted of BMWs, a car which many would so love to make a reality but which will remain forever in their dreams. Plus ça change.