Can I get a 5-year-old case dismissed in Orange County CA?

This is called a Serna Motion, failure to arrest within one year. Normally, it requires you to have lived in the same place as you gave as your address when you were released after they sobered you up. If you were there over 1 year you may have a good chance.

You should hire a local attorney who can review any statute of limitations or speedy trial violations that may be evident in the court records as to why nothing was filed by your original court date. Without reviewing the court record, it is difficult to tell whether or not your rights have been violated.

An attorney should get you some information on this during your free consultation. An attorney will have to find out where the case is in the system. Depending on the facts this may or may not be dismissed. Hire an attorney or go to the Public Defender to have the case reviewed.

Maybe. There are several cases that discuss the diligence of the Government in prosecuting cases and the failure of the government to diligently pursue charges can result in dismissal, your facts may provide such relief. You need to discuss the facts of your case with an attorney to determine whether, or not, your situation fits into the factual scenario that can result in a dismissal. If not, you will still likely need to discuss the facts of your case(s) to clear the warrant(s) and determine what if any defenses are available to you and what the likely outcomes may be.

CAN the case end up being dismissed? Sure. Is that likely, just because you want it? No. You have provided no information that would indicate your legal and factual grounds for a Motion to Dismiss. If you have any such grounds, legal defenses, etc., we can discuss them If serious about hiring counsel. What you have described is an outstanding warrant issued for failure to appear. That is what happens when the defendant does not appear in court when required. Your court file will almost certainly show a letter was sent to you at your address on file, with Notice of a court appearance date. You either did not get it, or overlooked it somehow. To handle a warrant properly, you must turn yourself in to the issuing court, with or without an attorney. You'll try to negotiate a recall of the warrant[s] and bail reduction or OR release. You'll try to negotiate a plea bargain on any Failure to Appear? charge or probation violation that caused the warrant. You'll try to negotiate a plea bargain or take to trial the outstanding charges that caused the warrant. Effective plea-bargaining, using whatever legal defenses, facts and sympathies there may be, could possibly keep you out of jail/prison, or at least dramatically reduce it. Unless you're competent to effectively represent yourself in court against a professional prosecutor trying to put you in jail, most people hire an attorney who can.