How do you know which jiggler key will open what car?
1st the year of the car will help as well as knowing whether or not it uses automatic locks. Automatic locks sometimes are setup in such a way that jigger keys will be difficult if not impossible to use. My motto is the older the car is the better. 2nd examine the Key hole. from observing the holes size, shape and also length (if you have a tool on hand to check depth). After that use the appropriate key depending on whether the lock uses a long key with many tumblers, a dual sided tumbler or wafer lock, or if it uses your basic one sided 5 tumbler lock. then simply use the jiggler key while gently applying pressure.
If all else fails, call a locksmith. .