LONDON  With his canary yellow Ferrari at rest in the forecourt of one of the most expensive hotels in London’s upscale West End, its eight-cylinder, race-bred engine burbling, a young Arab man who gave his name as Khalefa spoke with whimsical regret about the array of even faster, more expensive super cars parked nearby that belonged to other young men like himself from the Persian Gulf oil states.

“Me, I only have the Ferrari,” he said. “I am a poor man.”

With Britain still struggling to climb out of recession, and the new governing coalition embarked on a historic campaign of budget austerity, wealthy young men like Khalefa  who declined to give his full name, or his nationality  encounter a conflicted reception when they flee the conservative social mores and the 130-degree heat of the Middle East in high summer to enjoy the cool breezes of millionaires’ row districts of London like Belgravia, Mayfair and Knightsbridge.

On one hand, the young men and their families get an eager welcome in the hotels, department stores, and jewelry and fashion boutiques that rely heavily on the visitors’ wealth in otherwise lean economic times. Many local people, too, at least in London, enjoy the excitement and panache that come with a parade of exotic cars with Arabic license plates from gulf oil states like Saudi Arabia, Kuwait, Qatar and, especially, the United Arab Emirates.

But a display of vehicles that rival anything to be seen at the Pebble Beach Concours d’Élégance or Monaco’s Casino Square at Grand Prix time has its downside, too, with residents complaining that some visitors have exploited the easygoing atmosphere of the West End in summer to flout parking regulations and stage what have amounted to races of their own in the deserted streets after midnight, in what one of Britain’s tabloids called the Knightsbridge Grand Prix.