Ask HN: Flying Car Practical Tech

In this presentation, Elon Musk briefly mentioned a practical benefit of the new flying car, at minute 8:45: https://www.youtube.com/live/qt5p-_tE8d0?t=525

"The actual benefit ... where the downforce of the car ... because the car sticks to the ground so hard."

Could anyone who understands the technology expand on that and explain it in simple terms for non-experts?