>>4474803 (OP)
Her foot lands too low. Her leg can't come straight down the side of the car and then her foot ends up that far away from it. But you need her ass to be on the hood, so either you need to shrink her or hope no one notices your mismatch.
To put it in terms 4chan understands, you can stretch a models labia til it wraps around a horsecock but in the end the girl can't end up being bigger than the horse if she's supposed to be bellyriding it.