My brother wants to buy a car, should my sister help?

This depends on personal circumstances.

If my younger brother is a person who needs a car very much, and I have a certain economic foundation, even if my parents don't talk, I will lend him money to buy a car, because this is the need of his work.

I can see my brother's efforts and his positive attitude, so even if my parents say nothing, I will choose to let my brother buy a car to help him improve his work efficiency.

If my brother is a lazy man and my parents help him and let me pay for a car, then I won't agree.

Because this not only didn't help my brother, but hurt him, making him feel lazy and get whatever he wants, and also making his parents feel that I have unlimited financial support here as long as they ask.

If my brother is not diligent, motivated and lazy, no matter what my parents say, I will not agree.

Even if I have enough financial support, I won't agree, because I can't help him all my life. I want my parents to know that they are not doing this to help my brother.

I also want my parents to know that what I have does not mean that it is my brother's. They have no right to choose to let me give all my things to my brother. If I think my brother can't pay back, I will think twice before you do.