Designing and building a car from scratch involves a lot of perseverance and trial and error, so don't be discouraged if yours doesn't work perfectly right away. Experiment to see if you can improve the design of your solar car. How fast does it go? Does it drive straight? How would it perform with only one solar cell? What if you used smoother wheels for less friction? Keep testing new ideas to make your car work better.
Once you've perfected your car, think about other ways you could experiment with solar power. Could you build a solar boat or water pump? Could you perform electrolysis to divide water into hydrogen and oxygen using a solar panel? How can we harness the amazing power of the sun? Maybe you'll be the next scientist to help find out!
For more solar science fun, check out these projects: