You will likely need the assistance of an attorney in the jurisdiction where you received the citation. If you cannot afford to hire an attorney, the judge will appoint one from the public defender's office when you go to court. However, the 30 day impound will probably be over by your first court appearance. You, or an attorney may attempt to speak with the police department to see if they will release the hold. An attorney may be able to assist you with this and have the charge reduced to an infraction instead of misdemeanor. A misdemeanor may have serious employment implications in the future. Good luck!

Whether one's motoring conduct is a speed contest or not, for citation purposes, is highly subjective with the cops, unfortunately, and they are given a great deal of leeway in what they can do to people while exercising that subjective opinion. You need to hire counsel immediately, because not only will you lose the use of your car for that period [for which you'll have to pay storage and towing fees], but speed contest allegations, in the wake of several notable deaths over the past couple of years, are treated very seriously by the criminal courts. Don't try to muck around in that confusing labyrinth on your own.