dont know how you kept your cool when you were watching this happen..I would have been arrested!why didnt you accidently let the trolley go into her car?lol
anyway,rules I follow at the centers
never park close to a trolley bay
park as far away as possible to entrance or other cars.
try to park in some obscure or last spot with as much gap as possible to other cars.
park "illegally" if possible.most shopping centers are not council and their security dont care for people that dont park in proper spots.they are car nuts like us as well!! ha