As Scarlet drives in this clip, she often raises her boot a few inches from the pedal and stomps it to the floor. She holds it pinned to the carpet as long as she can before letting off. She doesn’t raise her leg up, she flexes at the ankle when she does this so. You hear a ‘thump’ of the sole of her boot hitting the pedal and then a ‘thump’ from the pedal hitting the floor.
When she’s ready to leave the store, she’s parked next to a young kid who has an odd look on his face while Scarlet is trying to get the Caddy cranked. It’s a little flooded and takes a little work to get it going but fortunately not too much as this kid is making things really awkward. She backs out of the spot and drives it like she did earlier, flooring it when she can and stomping the gas pedal!