One thing re probable cause, Paige.. In Georgia, there is an "implied consent" law. The legal theory is that by obtaining a drivers liscense, one gives implied consent to being tested for too much alcohol..(DUI)...including blowing into a device, standing on one foot and singing old macdonald had a farm, counting backwards, etc.
If DUI, they can pat you down and handcuff you. They can look in your windows, but they cannot do a search of your car. That requires a warrent, and the reading of your rights.