The blue license plate is a private car, and only some informal driving schools or coaches will use private cars to let students practice their hands.
For example, there are many shops selling dog meat by hanging sheep's heads. In fact, the official of Xiaokunshan Driving School has not opened any stores. And many students who learn to drive in a few days by chartered car are very cheap. In fact, they all go to other places to test their driver's licenses, borrow venues in Shanghai, and even look for new roads that have not been opened. They use private cars to do basic exercises for students, and then let you take exams in other places. If you fail in the test, they will ask you to give the instructor a red envelope and spend money to pass, because there are many loopholes in the invigilation of driving tests in other places. Most of these places are northern Jiangsu and An Wei, which are close to Shanghai, such as Lu 'an driving test, and there are many agents in Shanghai.