You can generate money with a car or a farm. The whole problem with capitalism is getting money without working because you let people work with your stuff. So owning a car and use ist as a taxi is fine with communism. Having a taxi company is not. But you can form a taxi company with others. The difference is no one has financial power over others. No one just profits because he/she is the owner. There are people in charge but they are in charge because they have the knowledge and ability not just because they own everything and can do what they want.