"Passengers come from all walks of life, including business people, government officials and doctors. Sometimes a passenger will be someone you can do things together with or who can give you tips on various things, for example starting your own business."

Yuan says he draws on his experience as a car salesman to dispense advice on anything to do with cars to passengers.

A relationship between a car-hailing app driver and a passenger is a little more intimate than that between a taxi driver and a passenger, he says, in that the car-hailing app drivers will have the mobile phone numbers of their customers and can contact them immediately if, for example, they leave personal belongings in a car.

"The service does not stop just because you have got out of the car. Some apps even have chauffeur service, and we offer bottled water, electrical charging and tissues."

His decision to drive fulltime was based on pure economics: if he drives part-time, he says, he will make less money, and fears of government curbs on car-hailing apps is a constant worry. As the number of app-using passengers grows and more rules are imposed, the software companies have become less generous with their payments, so the financial returns are much less attractive, he says.

"The market for car-hailing apps in Beijing is a bit chaotic. The threshold to become a driver is getting lower and lower. Some drivers even cheat by taking fake orders to get bonuses. and that is unfair to the honest ones. There is no doubt that car-hailing is a good thing, but the market does need to be regulated."

Recently, eight government departments in Beijing, including those responsible for transport, industry and commerce, met officials of Uber and Didi Kuaidi, the companies that own the two most used car hailing apps in the country, and read them the riot act, saying them of being involved in unauthorized business practices, tax irregularities and sending spam messages.

Company officials are understood to have expressed their willingness to work with the authorities and to regulate their businesses.

Several weeks ago Shanghai cracked down on unlicensed ride services offered through car-hailing apps. Drivers caught faced fines up to 10,000 yuan ($1,600) and their driver's license being confiscated for up to six months. The company that the drivers signed up with were liable to fines up to 100,000 yuan.

Since November, legal authorities in Shanghai say they have caught 199 car drivers conducting unlicensed operations with car-hailing apps including Didi Kuaidi and Uber.

The Beijing Municipal Transport Law Enforcement General Team says that this year 1,211 drivers have been caught using Didi Kuaidi to conduct unlicensed activities, and 170 drivers have been caught using Uber to do the same thing.