Is it necessary for cars to be sealed and soundproof?

Sealing is a sound insulation means. If the car is not too expensive and you don't want to spend money on professional sound insulation, you can stick your own sealing strip.

However, if the car is a little better, it is still recommended to do professional sound insulation instead of sealing strips. Because the body is over-sealed, it may have a certain impact on the ears inside the car and produce an uncomfortable feeling.