One strategy would be to throw the keys to your car as far away as possible or kick them under a car. Anything to keep from being dragged into the car.
I had a friend who did that. The would be abductor scrambled off to find the keys and my friend ran back to the store and called the police. It certainly worked in that case.
I agree, I told my girls long ago to throw those keys as far as they could, even if he knocks you in the car try to drop them on the ground or throw them in the back seat. Anything! Just fight for time. Another thing that needs to be mentioned is for young women, and maybe older ones also, to be alert while shopping. Make a point of entering several stores or several different departments before you exit, not to shop, but to verify no one is following you. If you pay attention it is very easy to identify a stalker. DO NOT leave the safety of the mall or shopping center if you identify such, call the police and wait for an officer to show up. You might even catch one of these creeps and save some young woman’s life!