Your car will jerk a lil and just go on moving.

If you believe the "It won't last long" bullcrap, then knock yourself on the wall cloudx. Dad did it for 15 years already, on those big accords, till today it's fine.

He does it when the car's rolling pretty fast and reaching a traffic light, or when going downhill, just watch your brakes. Saves petrol i guess, marginal tho