i have been told that goo off will damage paint work.
i have read a restore webpage and the fellow uses it to remove milar. the site seem to be down at the moment but here is another link that refers to it
http://www.xmission.com/~daina/tips/pub/tip0544.html
the person on the page this link refers to has done several mylar removals
anyway i bought some off ebay. 16 ounces for about $29 au including shipping 4 X 4 ounce bottles.
one link says the spray bottle but the other uses normal bottles.
i will be trying this on an old playfield first.