I think you have new shoes or something like that
But it can easily be fixed in 2 ways:
1. Take it like a man and especially when it´s dark watch closely and put your finger very slow on the metal. The lightning striking you is "harder" then and it looks quite cool!
2. Open your door and get your hand on something with Metal. In my car it´s the door handle. If it is made of plastic in your car, grab the metal of the door and THEN put the foot down. Nothing will happen then. The electricity still goes through your body, but you will not notice it.
Remembered when grabbing the door fast it doesn´t hurt as much? The slower you do it, the harder the strike is, but the cooler it looks :-) If you use the "grab some metal before putting the foot down to exit the car" method you won´t get that nice visual effects, but it will solve you problem