Best to consult a LOCAL Traffic Ticket Attorney - many offer free consultations. Can locate a local attorney right here on AVVO under the tab "Find A Lawyer"
This is not intended to be legal advise or as legal representation. I am a California personal injury attorney . Be aware that every state has its own statute of limitations; and statutes & case laws that govern the handling of these matters.
It is not a moving violation. There is no reason to take a defensive driving course for a non-moving violation. You will not get points on your driving record. You can just renew you inspection, go to court and see if the prosecutor will dismiss you case. The worst thing that will happen is that you have to pay a fine. Even that is usually negotiable if you go and speak with the prosecutor. You should not hire an attorney for a simple case with no consequences. This advice is good as long as the only violation was for an expired inspection sticker. Good luck.
Legal disclaimer: My answers are only intended as general legal advice based on my experience. They are not intended to be a binding legal opinion nor to create an attorney-client relationship.