It would be real nice if the Theme Options->Header->Search functionality was configurable so that I could have the usability of an integrated modal popup but use the Google Search code instead. I ended up adding a menu entry with the spyglass icon to a page with the google code.
The menu entry looks like:
<i class=“x-icon-search” data-x-icon="&xf002;" aria-hidden=“true”><i>
The code in the search page, embedded using Woody Snippets within a div:
<script async src=“https://cse.google.com/cse.js?cx=xxxxxxxxx”><script><div class=“gcse-search”><div>
I also have a script run at page load to replace the Google Search comment with my own text:
<script>window.onload = function(){ document.getElementById(‘gsc-i-id1’).placeholder = ‘What would you like to find?’; }</script>