Can I be convicted of DUI if I was in my parked vehicle in my driveway with the motor off?

Unfortunately officers still issue DUI citations in these matters, but in most states the issue is whether or not you were "operating" a motor vehicle while under the influence of alcohol or drugs. If the engine was shut off, and the car parked and not in any motion, then I suggest your or your attorney hold a motion hearing on this matter for the Judge to decide if your were actually "operating or driving" your vehicle at the time the officers arrived. If you were not, then there is a possibility your case could get dismissed prior to trial.