function ajax_scripts(){

 wp_enqueue_script( 'wbajax', get_template_directory_uri() . '/js/wiperblades.js', array('jquery'), true );
 wp_localize_script(
  'wbajax', 'frontEndAjax',
  array(
   'ajaxurl' => admin_url( 'admin-ajax.php' ),
   'nonce' => wp_create_nonce('ajax_nonce')
  )
 );

}
add_action( 'wp_enqueue_scripts', 'ajax_scripts' );


function wiperblades_form() {

 $wbform = '<form id="wiperblades" action="">';
  $wbform .= '<select name="manufacturer">';
   $wbform .= '<option value="">Select Manufacturer</option>';
   $wbform .= '<option value="1">Audi</option>';
   $wbform .= '<option value="2">BMW</option>';
  $wbform .= '</select>';

  if( !empty( $_POST['manuf'] ) ) {
    echo $_POST['manuf'];
  }

 $wbform .= '</form>';

 return $wbform;

 wp_die();

}
add_action( 'wp_ajax_nopriv_wiperblades_form', 'wiperblades_form' );
add_action( 'wp_ajax_wiperblades_form', 'wiperblades_form' );

$(".search-div select[name=manufacturer]").change( function(e) {

  var manufacturer = $(".search-div select[name=manufacturer]").val();

  jQuery.ajax({
   type: 'POST',
   data: {
    'nonce': frontEndAjax.nonce,
    'action': 'wiperblades_form',
    'manuf': manufacturer
   },
   url: frontEndAjax.ajaxurl,
   success: function(msg){
    console.log(manufacturer);
   },
   error: function(ts) {
    console.log(ts.responseText);
   }
  });

 });