I've had an FLHT(if I recall correctly) mounted for a few years now with no inner liner. Had to modify the bottom of it to remove the apron that came down over the HD forks. I already had the Kewl Metal windshield mount in place of the OEM, so I just cut some SS strap to the length needed and bolted it to that shield mount. Still had a small amount of vibes at speed so added a P clamp on each side of the handlebars and attached them to the windshield bolts using another short piece of SS. It's solid now.
This is an old picture, but gives you an idea.
