If I am reading this right, you want to know if you can get an old dui/hit and run expunged from your driving record. The answer, unfortunately, is that nothing can ever be expunged from one's driving record. It just ceases to be important once you get outside of the lookback period.
You should be eligible to get it off of your criminal record,
which is easy enough to do. You don't even need a lawyer. California runs its own very handy, free do-it-yourself expungement self-help center.
It's on the web complete with all necessary forms. I have provided you with a link to it. It will allow you to check your eligibility for an expungment and then get step-by step directions, including links to the downloadable forms you'll need.
When you use the link above and get to the home page, click on "Criminal Law" from the column on the left. Then click on "Cleaning your Criminal Record," scroll down towards the bottom of the page to the links and expand them so that you can see all of the steps.
As I have said, though this can result in a dismissal and would allow you to say you'd never been convicted of a crime, the incident would remain on your driver's abstract. There's just nothing, unfortunately, that can be done about that.