If you’re ever , there are a few things you need to watch out for on the way in. First, that you’ll have to pay if you go to the city center, then (ULEZ) fees that were expanded last month to cover the majority of the UK capital. Now, an armada of rich people armed with their shiniest supercars have swarmed London to protest that expansion and highlight some of its shortcomings.

The in the capital since it was expanded to cover every borough as well as the City of London. Its expansion means that thousands of motorists will (about $16) per day if they want to drive into the city, as well as the £15 it costs for the Congestion Charge in the center.

Of course, there are certain , and the mayor of London, Sadiq Khan, will allow you to drive into the city free of charge if you have a gas-powered car that compiles with the Euro 4 standards, which were introduced in 2005. Diesel cars must be Euro 6 compliant, which came into force in 2015.

In simple terms, this means you’ll probably have to pay the fees if your gas-powered car is from before 2006 or your diesel motor was built before 2015. Anything newer probably won’t have to pay the fees and neither will anything .

It should come as no surprise then that people are a little mystified at the various exemptions on offer to drivers in the UK capital. To highlight some of the more left-field models that are exempt from paying the $16 fee, London’s rich people assembled to drive their Lamborghinis, Mustangs and even a into the city.

, the armada of supercars that descended on the city was part of a protest organized by Ciro Ciampi, the founder of the Petrolheadonism Club. The protest saw drivers parade their cars from Regents Park to Downing Street, as Autoevolution reports:

They protested, but they also celebrated the awesomeness of the cars, as Ciampi says. This was the petrolheads’ way of showing solidarity with the average working person, who will be the most impacted by the ULEZ expansion. Previous protests have also called the expansion a “bogus war on the motorist,” paving the way to banners like “Stop the clean air lie,” also used at Sunday’s protest.

The drivers of these luxury motors are seemingly just as confused as you and I about why are exempt from the fees, while people stuck with nothing but a knackered old Ford Fiesta to get to work have to cough up the extra charges.

Clearly, charging people as a deterrent for driving into a heavily-congested city is a good idea and should be used to cut emissions in crowded areas. However, London’s model definitely has some gaps that need plugging before it can be considered a successful way of encouraging drivers off the highway and into public transport instead.