As you operate your car, you need to push down on the pedals, which also pushes back against your buttocks and lower back. Since you're applying pressure with your foot, it's actually causing more pressure on your buttocks than if you were simply sitting there passively. For this reason, you should stay out of the driver's seat for at least a few weeks after your BBL.
The Butterfly BBL technique aims to target a lack of volume and fat tissue in the upper regions of the buttocks. It is called the butterfly lift because just as a butterfly opens its wings to display bigger wings on the top, the higher wings protrude more so than the lower wings. Therefore this specially formulate butt augmentation procedure aims to augment the buttocks higher portions leading to a more proportionate butt appearance.