one day I just removed my car from parking infront of a shopping store. my manager came, he parked his car in parking, I came out from car and start talking with him. my car was at my backside. there was slightly slope towards my car. one shopping cart was there maybe 15-20 feet. pressure of air came and shopping cart start to move towards my car. suddenly my manager tell me "your car" I saw that side, when see cart is going towards my car, start running towards that and hold that just from 6-7 inches from my car front door. if I delay 2-3 seconds, cart should be damage my car door. speed was enough to make dent.