Chinese people love cars and everyone wants to own their own. They represent riches, freedom, independence. Unfortunately, they bring with them a number of problems, pollution, noise, traffic, but to most Chinese, these things are a small price to pay. Those that can afford to buy a car are doing so, those that can't are saving up and patiently waiting for the day that they can. Therefore, when the mayor of a city as prosperous as Shenzhen comes out and tells the people of Shenzhen that they should stop buying cars (Chinese only), it creates a big stink in the media.
His reasoning is based on 2 main things: the traffic and the enivornment. Traffic in the city is getting worse and worse and the more cars on the roads could lead to a decline of Shenzhen's currently very livable conditions. The mayor admits that this isn't a ban and he doesn't have the right to stop people from buying cars, but its more an attempt to encourage people to stop.
The problem is that he misses the main problem. The problem isn't with people owning cars, its with the number of people who end up driving those cars to work, instead of just using them for night/weekend transportation as in the case in most large cities around the world. The reason why? The abundance of cheap parking in the city.
A boss (like mine for example) living in OCT (Overseas Chinese Town, where much of the high end housing is located) is not going to take the subway into town and be amongst the "riff raff." A cab ride from there and back will probably run him close to RMB100 a day. However, he can probably find a place to park amongst the small, older apartment complexes that are within a few minutes walk of Diwang (Shenzhen's main building) and the Stock Exchange. How much would he pay for such prime parking? In a place like New York or Chicago, it may cost him in upwards of US$50 or even more per day, creating a major dissincentive for him to drive to work. But this is China, so how much does it cost? RMB50. Yes, that's right, when compared to cabbing it, he'll actually be saving money. After work if he wants to stop off at a bar or restaurant and needs to leave the car in a paid parking lot, he'll probably be paying less than RMB10.
Economics would simply say get all the people running the parking lots together, create their monopoly, and jack up the prices. The reality, though, is that these "parking lots" are often individually leased out by people who have apartments in these nearby older apartment buildings (or by the building owners), but don't have cars, so instead they rent them to workers in the building. Thus, its not going to be easy getting all these individuals together, unless the city takes over parking operations for downtown.
As long as parking continues to be so cheap, more and more people will go out and buy cars and, even worse, will drive them to work on a daily basis. Let's just hope positive measures are taken in other areas to keep Shenzhen green.