@Soulfox -- A big exception to that rule has to do with a DUI expungement. If you get a DUI charge, courts are not so forgiving and will probably not set up a way to get those things expunged from your record.
That is because a DUI (or DWI in some states) is considered a serious offense. Having one of those follow you around can be a problem. It might get harder to get a driver's license, get a job or do a lot of things.
The best move is to not drive under the influence of alcohol to begin with.