title: Passing query parameters in a cross domain tracking setup
body: <p>We have two websites which are configured for Cross Domain Tracking using Google Tag Manager. So at some point after the window load event, Google changes all the URLs that have to be cross domain tracked by appending a Client ID.
  My question was however, how do we pass a query parameter from one domain to the other without breaking the cross domain tracking setup? For ex. coupon codes, etc.</p>