autoterminate-google-instant-search.user.js

// ==UserScript==
// @name           Auto-terminate google instant search
// @namespace      http://uu59.org/
// @version        1.0.0
// @include        http://*.google.*/search*
// ==/UserScript==

(function(){
  if(! location.hostname.match(/^www\.google\.[a-z]{2,3}(?:\.[a-z]{2})?$/)){
    return ;
  }

  var xhr = new XMLHttpRequest();
  xhr.open('GET', '/preferences?hl=en', true);
  xhr.onreadystatechange = function(){
    if(xhr.readyState == 4) {
      if(! xhr.responseText.match(/name=suggon value=2 checked/)){
        // already enabled
        var setprefs = document.querySelectorAll('a[href^="/setprefs"]')[0].href;
        window.location.replace(setprefs);
      }
    }
  }
  xhr.send(null);
})();