How many cars can you own?
As many as you can afford. Property taxes, license and insurance are the only requirments. There is no limit to how many you can own. Jay Leno has a warehouse full of them.
Many people in China own cars. In the past, prior to the 1980s, very few Chinese people owned cars, but as China's economy grows and Chinese people's lives are improved, more and more Chinese people can finally afford to own a car. However, there are still a LOT of bicycles in China. I would say that more Chinese own a bicycle than own a car.