To do this you first need some images and no source code. You just have to change the images at the right time (e.g. when a key is pressed down). If you want us to help you with this part you have to be more specific. What exactly is the problem?

Normally, it is just a matter of removing and adding the something/someone from the world. The Car class will have a boolean or Object reference (to hold the something/someone) which can be set by method call. While value is true or not null (depending on type of field) the car is controlled; otherwise it does nothing. Having the something/someone saved in a reference in the Car class has the advantage of adding it back into the world when needed.

Can you how it is done? I want to, by pressing a key, make an image (thief) walk to a car, open the car, enter and ride away. Then, if the car stops, by pressing an other key, let the thief step out of the car again. Thanks in advance for your help. cheers