You can’t file this one neatly under any familiar label: this 1989 Boschert B300 Biturbo Gullwing starts life as a Mercedes 300 CE, gains gullwing doors and now heads to Villa d’Este 2026 for sale. The appeal goes well beyond the visual theatre. Its one-off status, mechanical specification and backstory make it a collector’s piece that is as intriguing as it is difficult to price with any real detachment.
Among the latest automotive headlines, this deserves more than a passing nostalgic glance. What really matters here is the rare meeting point between 1980s coachbuilt ambition, Mercedes mythology and an auction market that has always had a soft spot for cars nobody could realistically recreate today.
Villa d’Este spotlights the Mercedes Stuttgart never built
Of the more unusual entries lined up for the Concorso d’Eleganza Villa d’Este 2026, the Boschert B300 Biturbo Gullwing stands out straight away. Broad Arrow Auctions will offer it with an estimate of 475,000 to 525,000 euros, which rather tells its own story: this is not being treated as a mildly tweaked Mercedes coupé, but as something altogether more singular.
In practical terms, it is a unique 1989 car built on the foundations of the Mercedes-Benz 300 CE. The inspiration is plainly the 300 SL “Gullwing”, Mercedes’ untouchable icon from the 1950s, but this is no retro replica. It is a very 1980s reinterpretation instead, complete with the flair, excess and faintly outrageous confidence that implies.
The Boschert project turns the 300 CE into a styling statement
Behind the car was German engineer Hartmut Boschert. His brief seems to have been simple enough: take a contemporary Mercedes and turn it into something more exclusive, more dramatic and more theatrical than the donor car ever intended to be. In other words, the 300 CE was the starting point, not the boundary.
Shown at the Frankfurt Motor Show in 1989, the B300 Gullwing wore heavily revised bodywork. The front end came from the Mercedes-Benz SL R129, while the roof and rear were shortened to give the car a lower visual stance. The finished result has the air of a concept car that somehow escaped onto the road. It is recognisably Mercedes, yet it also looks like it was designed without a marketing clinic looking over anyone’s shoulder.
The headline feature, naturally, is the electrohydraulically operated gullwing doors. That is the detail which lifts the car from expensive tuning special to genuine automotive oddity. It also separates this example from the other Boschert B300s built, nearly all of which used conventional doors. That distinction is not trivial when it comes to judging what bidders may be willing to pay.
Its twin-turbo straight-six belongs to a more straightforward era
Under the bonnet, this Boschert uses a 3.0-litre straight-six derived from Mercedes-Benz’s M103 family. The material provided points to a sequential twin-turbo set-up and an output of 283 ch. For the period, that was already a serious figure, particularly in a car conceived as a statement coupé rather than a mere styling exercise.
One detail does need careful handling. An image caption in the original material referred to a “twin-turbo V8”, but that clashes with the fuller description of the M103 straight-six. With no supporting source to back up the V8 claim, the only coherent specification in the file is the 3.0-litre six-cylinder with 283 ch.
Boschert B300 Biturbo Gullwing (1989), the cabin with the manual gearbox
The tuned mechanical package is central to the car’s identity
A closer look at the gullwing door mechanism
Drive goes to the rear wheels via a five-speed manual gearbox. In many ways that may be what makes the car so appealing now. The layout is easy to understand, the engine remains a properly worked combustion unit, and there is no mention of modern electronic interference. It is the sort of analogue performance car that asks more of its driver than a tap on a screen, which is precisely the point.
Its value rests less on numbers than on total uniqueness
You could focus on the styling or the engine, but that would miss the main argument for this car. What really pushes the Boschert into another category is its absolute singularity. Even when new, it reportedly cost more than the most expensive Mercedes models in the catalogue. That alone says plenty about the project’s ambition: Boschert was not trying to build a sensible alternative, but a showcase piece.
That changes the equation on today’s market. A rare collector’s car can still be measured against comparable examples; a one-off slips partly outside those usual benchmarks. That is both its strength and its weakness. The value can climb because it is irreplaceable, but it also depends heavily on how much confidence collectors place in its story, condition and paperwork.
Its history adds appeal, while leaving the usual one-off questions intact
The car first lived in Germany before being kept for more than two decades by an enthusiast who had first seen it as a child in a magazine. That sort of ownership story does count for something. In the collector world, a car preserved out of affection rather than pure opportunity often carries a little more credibility. It is not proof of anything on its own, but it is certainly a useful signal.
Sold on in 2023, it now shows a little over 39,000 km, described as original. Again, that adds to the attraction without settling the matter by itself. The real point is the combination of minimal production — in this case, just one car — unusual specification and long-term preservation. That trio is often what moves bidding more convincingly than the badge alone.
Boschert B300 Biturbo Gullwing (1989): an interior steeped in 1980s character
The 2026 sale will show how far buyers follow automotive outliers
The auction is scheduled for Saturday 16 May 2026 in Cernobbio, during the Concorso d’Eleganza Villa d’Este. It is hard to imagine a more suitable setting: elegant, highly visible and full of buyers who appreciate cars with a strong story behind them. In that company, the Boschert does not feel like an indulgent oddity. It almost makes perfect sense.
The familiar uncertainty, though, remains. How far will bidders go for sheer exceptionality rather than factory-sanctioned historical importance? A rare official Mercedes does not play by quite the same rules as an independent creation based on one. That is the dividing line between a collectible endorsed by the manufacturer and a flamboyant statement from an outside engineer. One reassures. The other intrigues. And sometimes intrigue is worth more.
In summary
- The Boschert B300 Biturbo Gullwing is a unique 1989 car based on the Mercedes-Benz 300 CE.
- Broad Arrow Auctions will offer it at Villa d’Este 2026 with an estimate of 475,000 to 525,000 euros.
- Its most dramatic feature is the electrohydraulically operated gullwing doors.
- The coherent mechanical specification in the file is a 3.0-litre twin-turbo straight-six with 283 ch, paired with a five-speed manual gearbox.
- With a little over 39,000 km indicated, it combines extreme rarity, an unusual history and strong symbolic appeal.
- Its final value will depend largely on how much appetite the market has for unofficial Mercedes creations that are effectively impossible to find.
Ultimately, this Boschert will suit the collector who wants not a conventional classic Mercedes, but a very specific slice of German car culture. Something to drive differently, display differently, or simply own in the knowledge that nobody else will arrive in the same thing. Its greatest strength is its uniqueness; its biggest limitation is exactly the same. The sensible alternatives remain better-known classic Mercedes models with stronger documentation and easier market visibility. None of them, however, offers quite the same sense of a prototype made real.
