 The ripples in the glass of water caused by the "T. rex"s footsteps were inspired by Spielberg listening to Earth, Wind and Fire in his car, and the vibrations the bass rhythm caused.Lantieri was unsure how to create the shot until the night before filming when he put a glass of water on a guitar he was playing, which achieved the concentric circles in the water Spielberg wanted.The next morning, guitar strings were put inside the car and a man on the floor plucked them to achieve the effect.