A 1934 Mercedes-Benz 500K is due to go under the hammer at Bonhams' Mercedes-Benz sale in Stuttgart on 12 July, with all the proceeds being donated to charity.
The classic is expected to fetch as much as €3.6m, with all the money raised to be split between the Swedish Cancer Society and The Swedish Alzheimers Foundation.
The 1930s roadster was discovered by a Scandinavian enthusiast in the '70s and was soon fastidiously restored to its present condition. It has remained in the current owner's hands for 40 years, until its donation to charity next month.
The car was originally fitted with an eight-cylinder supercharged engine and was finished in Speedgray, but was later returned to the factory to have the 5.4-litre engine from the new 540K fitted, along with that model's aesthetic improvements.
Secretary general of the Swedish Cancer Society, Stefan Bergh, said: "This generous donation will help us get closer to achieving our vision of conquering cancer."
His sentiments were echoed by Liselotte Jansson, secretary general of The Swedish Alzheimers Foundation, who said: "We are utterly grateful for this generous donation, which will help us reach our goal of finding a cure for Alzheimers – the most common form of dementia."
