Well my method takes out the need for overlap checks so he can be next to the car. UID is an identifier for each object. Under your spawn police action you have set police.variable to car.UID.
You then have car with UID 999 and police with variable 999 for example so they relate.
Then you say police on destroyed, pick car by UID : police.variable and then turn animation off.
It is just a way of relating the police to the car, something which you don't have right now.