California - Cannot find person who hit me with their car

[Sotty08]

In April last year a fellow hit me with his car, their were 2 witnesses, and no police report. His details were taken. I have sent a registered letter to his address and it was never picked up. His numbers never worked. I did a person search online and his listed number didnt work.
I know his name and a bit about his career profile as well as his license plate number that day. Its all very strange that he is so illusive. If someone can offer advice or help to track him down I would be so grateful.