If you are comfortable with DIY, Bogar sells a precut windshield protection film. I installed one and had what I believed is excessive waviness. They sent a replacement that supposedly has an updated adhesive formula, but haven't had a chance to install it since my AGT has been in the shop pretty much the rest of the time after I installed the WPF. This is for the Air, unknown if they will offer one for the Gravity.
Installation was easy enough. Didn't need a heat gun to soften the film to lay flat. I do wonder if there might have been too much soap in the slip solution and it contributed to the increased waviness in the film.