You can try the dry ice method, it's not harmful to clearcoat by any means. Don't get your hopes up, as it probably won't work.

Most dealerships have paintless dent removal services that come through once a week to do trade ins/auction cars in preparation for resale. Ask your service advisor/manager at your local dealer if they have a reputable PDR guy in your area.

The best of them can make it look like nothing ever happened.