It’s usual for rare cars that enjoyed notable success in period to command big money today — but those that failed first time sometimes carry a stigma, thus reducing demand and therefore value.

Not so BMW’s 1950 folly, the 507. Built at the behest and encouragement of the American-based auto importer extraordinaire Max Hoffman (who played a part in the development of the Mercedes-Benz 300SL and the Porsche 356 Speedster, among others), the 507 was meant to challenge the SL for US sales.

But by the time it had been developed and produced, the beautifully engineered roadster with its aluminium body designed by Albrecht von Goertz needed to be priced at more than $9000 to be anything like viable – and even then BMW was still losing money. As a result a mere 252 507s were built, and inevitably they were only bought by the super-wealthy, meaning that the car attracted a disproportionately large number of celebrity owners. Two- and four-wheel champion John Surtees bought one with money given to him by MV Agusta for winning the 1956 World Motorcycle Championship with hillclimb meister Hans Stuck and motorcycling legend Georg Meier being among other leading racers to own these handsome cars.

Perhaps more famously, Elvis Presley had two (and gave one to Ursula Andress) while Fred Astaire, Alain Delon and the Aga Khan also bought them. So it’s no surprise that HRH Prince (later King) Constantine II of Greece was the first owner of this 1959 model due to cross the block at Bonhams. He ordered his 507 with dark silver paint and the options of a Nardi steering wheel and a Becker radio – complete with state-of-the-art electric aerial.

The fate of the car in decades that followed his exile from Greece as a result of the military coup of 1967 is unknown, but it was discovered in badly neglected condition by the current owner in 1989 before being treated to a three- year, six-figure restoration in the early 1990s.

Still painted silver when found, the car was refinished in the current ‘Federweiss’ and during the past 25 years it has become a familiar sight on the international classic car scene having taken part in numerous events, including the Mille Miglia, the Ennstal Classic and the Tour Auto (as well as appearing at eight international BMW 507 gatherings).

In 2018 Bonhams achieved a record £3.8m for the ex-Surtees 507, which had remained in his ownership until his death the previous year, following-up five months later by selling the von Goertz car for £2.3m.

Those cars, however, had exceptional provenance having belonged to key figures in the automotive world – and, of course, that was then and this is now.

But even if it doesn’t make a king’s ransom, Prince Constantine’s former carriage certainly won’t go cheap…

1959 BMW 507 ROADSTER

On sale at Bonhams, Zoute, Belgium. Oct 11
Estimate £1.7m–£2m

In the market for under-appreciated classics?

Here are some other ‘flops’ of their day that are finally getting recognition

2005 Alfa Romeo 147 GTA

£19,995
They look great and Alfa Romeo only sold around 5000 of these 3.2-litre V6-powered hatchbacks worldwide, meaning prices are now on the up.
alfaaid.co.uk

2002 Mazda RX-7

£55,000
Mazda’s answer to the Porsche 911 was just as expensive as its German rival, and nowhere near as successful. The third-generation car is still a beautiful thing though.
contempoconcept.com

1985 Rover SD1

£10,995
The SD1 was supposed to be a world-beater when it was launched, but had a fair few flaws. Now, of the 304,000 built, only around 310 remain registered in the UK.
cranerclassics.co.uk 

1966 Alfa Romeo Duetto

£40,250
Launched in 1966, Alfa’s Spider is a very underrated little roadster. It’s fantastic to look at, drove brilliantly and this one has already been lightly restored.
vsoc.nl