There was a time when driving a motor vehicle covered in Union Flags under Berlin's Brandenburg Gate might not have been considered an act of diplomacy. Indeed that time might very well still be now.
But such was the fashion in which Britain's new trade ambassadors - Royal Princesses Beatrice and Eugenie - began their newest career yesterday, following in their mildly disgraced father's footsteps.
The royal Mini (British invention, now owned by the Germans) is to tour Germany's 16 federal states over the next few months. "The Mini we are about to drive is just one example of the great things Britain and Germany can do together," Princess Beatrice told a press conference at the British Embassy in Berlin. "The campaign is our national effort to get people to come to the United Kingdom and enjoy everything we have to offer. We've got so much we'd love people around the world to come and enjoy - beautiful countryside, lively cities and some of the world's most wonderful museums."
The Princesses, aged 22 and 24, might be considered curious choices for trade ambassadorship, given the imbroglio that cost their father Prince Andrew the same job in 2011 - he was photographed in New York with his close friend, the billionaire financier Jeffrey Epstein who had just been released from prison for soliciting underaged girls. But David Cameron is said to have personally invited the pair to promote the tour, and it seems unlikely he wouldn't have known about elder sister Beatrice's, considerable trade experience, having undergone work experience placements both at the Financial Times and as a personal shopper at Selfridges.
"They are the fifth and sixth in line for the throne and are now part of that group of royals who are willing to go out and lend their support to the UK," said a Foreign Office spokesman.
German observers noted that the tour was being launched on the eve of David Cameron's anxiously awaited speech on Britain's future relationship with Europe, amid fears in Germany that many UK politicians and large sections of the public are bent on Britain leaving the EU. It should come as some comfort to them that the offspring of "Air Miles Andy" should be prepared to take such a short-haul trip.
The Prince was all too regularly accused of wasting taxpayers money by staying in five-star hotels and chartering private jets. He was also accused of exploiting connections he developed with wealthy trading partners for his own ends. He sold his house for Â£15m - Â£3m more than the asking price - to an oil tycoon from Kazakhstan. Since stepping down as trade ambassador, he has maintained an friendship with President Ilham Aliyev of Azerbaijan, regarded as one of the most brutal and corrupt rulers in the world. The prince has denied any impropriety.
He is believed to have lobbied for his daughters to spearhead the "Great Britain" campaign and is said to have been fighting a "rear guard" action to ensure that they represent the Royal Family more often. Yesterday's Berlin launch was their debut event.