A new study has put hard numbers on the most reliable argument in any car park, and Mercedes drivers have come out of it badly. Research by global car rental comparison site DiscoverCars.com found that 25 per cent of Mercedes were parked incorrectly, the highest rate of any brand observed.

Citroen came second on 24.4 per cent, which quietly ruins the theory that this is purely a luxury car problem. BMW landed third on 21.7 per cent, though not a single BMW was found parked in a disabled bay without a permit.

Tesla was fourth on 20.5 per cent and Volkswagen fifth on 20.4 per cent. The rest of the top ten ran Seat on 18.3 per cent, Ford on 18.1 per cent, Audi and Renault tied on 17.7 per cent, Peugeot on 14.2 per cent and Kia the best behaved of the group on 10.8 per cent.

BMW placed third on 21.7 per cent, though not one was found in a disabled bay without a permit. Image: BMW

The method is worth understanding before you take this to the group chat. DiscoverCars.com enlisted nine travel bloggers who observed 913 cars in busy car parks across Paris, Rome, Barcelona, Amsterdam and Manchester, recording the brand, whether the car sat inside the bay lines, and whether it occupied a disabled space without a valid badge.

That is a modest sample spread across five very different cities, and it does not appear to adjust for how many of each brand are actually on the road in each location. A brand with more cars in the car park has more chances to look bad.

Aleksandrs Buraks, Head of Growth at DiscoverCars.com, said the Mercedes result does nothing for the reputation luxury car drivers already carry, while pointing out that Volkswagen and Citroen sitting so high on the list shows the problem is not confined to premium badges. He also made the obvious plea about checking you are between the lines before you walk off.

There is a fairly boring explanation sitting underneath all of this. Luxury cars have grown enormously over the past two decades, and a GLE or an X5 is a genuinely wide vehicle being asked to fit into bay markings that were drawn up when a family car was the size of a modern hatchback.

Tesla came fourth, with 20.5 per cent of those observed parked incorrectly. Image: Tesla

Anyone who has tried to reverse a three row SUV into a shopping centre car park in Sydney already knows how that ends. The cars keep getting wider and the bays stay exactly where they are, which turns a two door opening into a negotiation.

None of that excuses the disabled bay findings, which are the genuinely poor part of the data rather than the funny part. Mercedes, meanwhile, has been busy at the other end of the seriousness scale, and we recently covered how Mercedes is turning the G-Wagon into a drone hunter.

The full report and the complete brand rankings are available at DiscoverCars.com.