@media only screen and (max-width: 480px) {
    #car1, #car2,#car3,#car4{
      height: 200px;
    }
  }

  @media only screen and (max-width: 720px) {
    #car1, #car2,#car3,#car4{
      height: 300px;
    }
  }

  @media only screen and (max-width: 920px) {
    #car1, #car2,#car3,#car4{
      height: 300px;
    }
  }