This is one of those situations where I feel like there is a simple answer right in front of me...hopefully you guys/gals can show me the light.
PROBLEM :
So - the answer here was this :
Like I said...I knew there was a simple example staring me in the face haha!
This question is old and obviously must have been solved by now by @aepearson. Adding another answer from current day perspective.
Now, one can also easily use sessionStorage also to save navigation data into a key. Pick it up whenever required, and add to url.
Example from Mozilla
// Save data to sessionStorage
sessionStorage.setItem('key', 'value');
// Get saved data from sessionStorage
var data = sessionStorage.getItem('key');
// Remove saved data from sessionStorage
sessionStorage.removeItem('key');
// Remove all saved data from sessionStorage
sessionStorage.clear();
If you just want to persist this exact query string on each page, why not set the linked pages to insert the string into a session variable. Then on each page link check to see if the session variable exists and add it to the query string when redirecting.