Grade 3 science project. How to build a magnetic powered toy car.

This project needs to run solely on magnets. It has to move forward and backwards, as well as turn left and right.Move a two different speeds ( fast and slow ). I know the magnets can be used to repel and attract but  i can't put the idea to paper let  alone help her build it .

Wow what kind of 3rd grade science class is your kid in? That sound more like a collage lvl engineering project.

Just build a regular RC car. It could be considered a "magnet" powered toy car. The motors would not work without a magnet and the wire coils in the motors create a magnetic field when voltage is applied.

I think more details about the assignment would help. Almost sounds like the teacher is trying to get there students to work out the problem they are having in there college course as they work towards a doctor-it.
Nothing can "run" on magnets - you need a source of energy. What was the official spec for the project ?