Views with exposed filter (ajax enabled) inside modal window

Hello,

I'm trying to load a view with exposed filters (ajax enabled) inside a modal window.
The first time when I open the modal windows, the exposed filters works ok, but if I close the modal and open again the exposed filters doesn't work anymore (no errors, just doesn't filter anymore).

I'm using

function mymodule_modal_add($js = NULL) {
  if ($js) {
    ctools_include('modal');
    ctools_include('ajax');
    $output = views_embed_view('add_car');
    ctools_modal_render(t('Add car'), $output);
  } else {
    return MENU_ACCESS_DENIED;
  }
}

Can anyone tell me what I'm doing wrong? Is possible what I'm trying to do?

Thanks.