I'm writing a few characters for a project of mine but I want them to feel interesting and a good way to go about that would be to add some flaws. What are some good flaws for a character?

So far I got a street racer that gets mild halusinations from flashing lights which I think might make some scenes more interesting with him since street races take place at night. So the faster he goes the faster the street lights flash the worse the halusinations get.

Thoughts and/or suggestions?