Like hen’s teeth
If uncommon classic cars are your thing, then this Bonhams|Cars auction will pique your interest.
It’s full of automotive rarities, including a one-off Ford Escort styled by Pietro Frua, a one-of-19 Porsche 911 turbo and some special-edition supercars.
Presented in chronological order, here are 14 seldom-seen cars that have all been consigned to The Bonmont Sale, which takes place in Chéserex, Switzerland, on 29 June 2025. Enjoy!
The catalogue pre-sale estimates are in Swiss francs (CHF); all currency conversions were correct at the time of writing
1. 1936 Bugatti Type 57 Berline (est: £170-230,000/€200-271,000/$230-312,000)
We promised some lesser-spotted classic cars, so let’s hit the ground running with this Bugatti Type 57 by Vanvooren, apparently one of just five survivors.
Two of these are part of the huge Schlumpf Collection, housed at the Musée National de l’Automobile, so you’re unlikely to see another at your local cars-and-coffee gathering.
The first owner of the car pictured here was Otto Graf, who came from a family of cheesemakers with close ties to Ettore Bugatti.
Graf became a German prisoner of war in 1944, when it emerged that a resistance group was operating from one of his family’s properties.
He sold the car when he returned to France at the end of WW2.
2. 1947 Allard K1 (est: £63-90,000/€74-106,000/$85-122,000)
According to The Allard Register, there are about 57 K1s still in existence.
Not quite as rare as the one-of-five Bugatti on the previous slide, then, but you’d be lucky to spot one in the metal.
The Allard K1 was a short-chassis sibling to the M-, L- and P-type cars, designed to bridge the gap between the marque’s road and competition models.
Restored in the mid-2000s, this example has recently been exhibited in the current owner’s classic car museum in Switzerland.
3. 1953 Arnolt-MG Coupé (est: £63-81,000/€74-95,000/$85-110,000)
The Arnolt-MG Coupé is based on the MG TD. That’s right, the open-top sports car with large, flowing wings and a tall, upright grille.
So, how did the TD become this sleek coupé? The answer is a mix of Italian styling and American money.
Coachbuilder Bertone and designer Franco Scaglione used the Brit’s running gear to create a pair of show cars, which convinced US importer Stanley ‘Wacky’ Arnolt to order 100 to sell Stateside.
In all, 103 (67 coupés and 36 convertibles) were built, including this restored example, now fitted with a Shorrock supercharger.
4. 1963 Ford Fairlane 500 ‘Thunderbolt’ replica (est: £41-45,000/€48-53,000/$56-61,000)
In the battle for ’60s drag-strip supremacy, dealer team Tasca Ford of Rhode Island fitted a Fairlane 500 with the 427cu in V8 from the larger Galaxie, which had been struggling against some of its Chrysler, Plymouth and Dodge rivals.
Bill Humphrey, who was a test driver for the Blue Oval at the time, proved the ‘Thunderbolt’ was up to scratch and Ford committed to building 100 examples to homologate the car for the Super Stock category.
This road-legal recreation is a replica of Humphrey’s original.
It’s got a glassfibre bonnet, a Mooneyes rev counter and a 351cu in Windsor V8 motor.
5. 1963 Mercury Colony Park Station Wagon (est: £27-41,000/€32-48,000/$37-56,000)
You’ll need a big parking space for this Mercury wagon – a rebadged version of the Ford Country Squire – complete with oh-so-’60s wood trim.
The load area is surely big enough to challenge a pick-up truck while the big-block V8 engine should provide enough grunt to shift this enormous lump at a fair lick.
The seller doesn’t know much about this car’s early history, but they can trace its story back to 1999, when it was bought by a Mr Marietta in Texas, USA, before it travelled to Canada and eventually Switzerland, where it is now.
6. 1966 NSU Wankel Spider (est: £18-27,000/€21-32,000/$24-36,000)
Think of a rotary-powered classic car and you’ll likely picture a Mazda in your mind's eye.
The Japanese marque’s sports cars became synonymous with the Wankel design, from the sleek 1960s Cosmo 110S to the ’90s RX-7 MkIII and beyond.
But did you know that German maker NSU was actually first to market with a rotary-engined production car, with the Bertone-styled Spider?
According to Audi (NSU merged with Auto Union in 1969), just 2375 were built.
When it was new, the NSU Wankel Spider’s engine suffered from wear around the rotor tips. Thankfully, this car’s motor has been upgraded to avoid these problems.
7. 1971 Intermeccanica Italia Spyder (est: £110-130,000/€129-153,000/$149-176,000)
Remember the name Franco Scaglione? He styled the Arnolt-MG Coupé we saw earlier.
This Intermeccanica Italia Spyder was penned by the talented Italian designer, too, whose CV also includes the Alfa Romeo BAT concepts and the Lamborghini 350GTV.
It’s not known how many of these Italian-American hybrids were built, but this one is reportedly unique in having a set of Ferrari Dino 246 tail-lights.
Its Ford Cleveland V8 engine is believed to be original.
8. 1974 Innocenti Mini Cooper (est: £27-32,000/€32-38,000/$37-43,000)
Don’t worry, your eyes aren’t deceiving you. This is a BMC Mini… sort of.
It’s an Italian-built version of the British classic, conceived to overcome import tariffs.
This is an unrestored Cooper 1300, Innocenti’s version of the Cooper 1275 ‘S’, and it has covered just 67,860km (42166 miles).
The Innocenti cars are more or less the same as the British-built originals, other than a few key differences: the Mini’s Latin counterpart got plusher upholstery and one large fuel tank, instead of the twin-tank set-up of the BMC Cooper ‘S’.
9. 1975 Ford Escort Monte Carlo (est: £45-54,000/€53-63,000/$61-73,000)
That’s not a typo. Believe it or not, this is a Mk1 Ford Escort, and in a gallery of rare classic cars, this one-off prototype is perhaps the star.
Built by Pietro Frua, who also styled the Maserati Mistral, it was displayed at the Paris motor show in 1971.
It was registered a few years later, shortly after it was sold to its first private owner.
Apparently, it was restored in 2003. Its current custodian added it to their collection of coachbuilt Italian classics in 2018.
10. 1981 Porsche 924 Carrera GT (est: £81-110,000/€95-129,000/$110-149,000)
A Porsche 924 turned up to 11, the roadgoing Carrera GT homologated its racing-car sibling for Group 4 competition.
Just 406 were built, and this three-owner car’s odometer has recorded just 84,000km (52,195 miles).
Available in black, silver or red, the Porsche 924 Carrera GT has a KKK turbocharger and Fuchs wheels from the 911.
This car’s suspension, front seats, exhaust system and paintwork have all been refurbished during the current ownership and it comes with a certificate of authenticity from Porsche.
11. 1988 Porsche 911 930 turbo ‘Flatnose’ (est: £150-200,000/€176-235,000/$204-272,000)
Another rarity from Stuttgart, this 911 Flachbau, or Flatnose, is one of just 19 targa-top turbos fitted with Porsche’s alternative front end.
The style first appeared on the 935 racing cars and was later available from the factory, after privateer and tuner Kremer Racing started offering conversions.
This highly optioned example also has a limited-slip differential, heated seats and a brown-leather interior – and it’s covered just 63,000km (39,146 miles).
12. 2007 Lamborghini Gallardo Superleggera (est: £120-140,000/€141-165,000/$163-190,000)
The Superleggera version of the Lamborghini Gallardo wasn’t a half-baked attempt at a special edition to drum up more sales for the Italian marque’s V10-engined supercar.
Engineers took the brief seriously: a carbonfibre engine cover, rear wing, doors, seats, sills, rear diffuser, plus magnesium rims, titanium wheel nuts and other weight-saving measures shaved 100kg (220lb) from the standard car.
Just 618 were built and this one was delivered to its first owner in Japan before it was imported to Switzerland.
13. 2010 Ferrari 599GTO (est: £720-810,000/€847-953,000/$979,000-1.1m)
In 2010, Ferrari resurrected the GTO moniker for the first time since the fabled 288 when it announced a roadgoing version of the 599XX racer.
Just 599 were produced and this was the 100th built.
Any uncertainty about whether the 661bhp 599GTO was worthy of the nameplate was soon crushed when people got the chance to drive it.
‘This is a genuine landmark car for Ferrari, and deserves the success it has already achieved. It’s also a bona fide addition to the GTO family, make no mistake,’ concluded Matt Prior for Autocar.
14. 2014 Spyker C8 Spyder (est: £360-410,000/€423-482,000/$489-557,000)
The Spyker C8 was a rare supercar from The Netherlands.
The doors open upwards, there’s an Audi V8 mounted amidships and there are plenty of references to the company’s aviation history.
This car has covered just 3600km (2236 miles) since it was new and it was last serviced in December 2022.
If you like the look of this Spyker, or any of the other cars in this slideshow, click here to view the full catalogue.
The Bonhams|Cars sale takes place at Golf & Country Club de Bonmont in Chéserex, Switzerland, on 29 June 2025.
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