How can I get a field element id?

There is a way to do this, but it does require JS and is a bit tricky.  in the JS where you setup smartyStreets, you can “wrap” the fields you want into a form.  Here’s a basic example:
     $(“.MemberMailingSection”).wrap(function() {
            return ‘’;
        });
    
    var liveaddress = $.LiveAddress({
            key: GetSmartyStreetsLicense,
        debug: false,
        target: “US”,
        addresses: [{
           id: ‘MemberStreetsSetup’,
        address1: ‘.MemberMailingStreet textarea’,
        locality: ‘.MemberMailingCity input’,
        administrative_area: ‘.MemberMailingState input’,
        postal_code: ‘.MemberMailingZip input’,
        country: ‘.MemberMailingCountry input’
        }]
        });

Now, for each field, I added a css class with the names you see.  I know smartystreets likes Ids (#), but this seems to work.  The “MemberMailingSection” is the css class of the column in the field editor.  

Hope this helps.