Depending on the model of your car, you can unlock it remotely with your cell phone. A colleague was at the curriculum fair (open house) at our school in Raeford on Tuesday night, and her son was in Eutaw Village in Fayetteville, locked out of his car. She put the remote clicker close to her phone, while he held his phone close to the door. I guess it works if your car uses sound frequencies (she has a Honda Odyssey).