function shuffle(list) {
  var i = list.length;
  while (i) {
    var j = Math.floor(Math.random()*i);
    var t = list[--i];
    list[i] = list[j];
    list[j] = t;
  }
  return list;
}

$(function(){
    $('#rentacar').append(shuffle($('.bnr', '#rentacar')))
})