Sunny Lo has never felt such regret. When he came to Beijing on August 3, he was told there were no cars available for him to rent on his stay during the Olympics.

"I tried to call different car rental firms, but the answers were the same - I can only rent a Mercedes-Benz S-Class after this month. It's far beyond my budget," said the Dutch Chinese representative of a European health food provider.

He arrived in Beijing from Amsterdam five days before the Games' opening, to help arrange his manager's accommodation and more importantly, to rent a car for them during the competition.

Cars parked at rental firm Hualei Bangde Car Lease in Beijing. [China Daily]

"I ought to have booked it two months earlier. That way, we could drive by ourselves freely rather than taking taxis," said Lo.

Beijing is to welcome more than 2 million visitors to the city to watch the Games. The sheer number of people combined with the new restrictions that came into effect on July 20 with the aim of easing congestion and pollution in the city, has meant that Beijing's more than 200 rental firms have been preparing for the opportunities. But some cars such as luxury vehicles are still short in supply, despite the fact that prices have doubled and even risen to four times the norm.

Car rental firms said the price increase was due to the robust market demand and the alternating, even-odd license plate ban.

"Most of our cars have been booked. There are not many choices left. The luxury sedans are rented out for a long time, the prices have even doubled from August 1," said a member of staff surnamed Zheng from the public relations department at Beijing Today's New Conception car renting chain store, one of the biggest groups in the capital.

He said there were a few economic cars available. But added, "I am afraid they will be booked over tomorrow."

According to Zheng, car hire has doubled in price as a result of the even-odd license plate limit. Cars are hired out for 48 hours.

"So the rent in my company actually has not risen so much."

The price to rent a manual Jetta from Zheng's has increased from 230 yuan per day to 479 yuan for 48 hours in August. The rental of a Buick GL8, the most popular executive wagon in the Chinese market, has gone up to 1,640 yuan for two days from a normal 780 yuan a day.

Customers are paying 2,100 yuan to lease an Audi A6 for 48-hours, more than double the previous price.

"Our almost 200 luxury sedans, including Audi, BMW and Mercedes-Benz were booked out far earlier, even during September. I am not sure if we have cars available for the golden-week National Day holiday this October," said a member of staff from the call center of First Automobile Leasing Company, the branch company of Bejing BeiQi Kowloon Taxi Co Ltd.

"We only have two Buick GL8 wagons left today," said the employee on July 31. "We cannot even provide the economic cars, such as Jetta and Santana during the Olympics."