Are you putting the fondant directly on the styrofoam? i coat my dummies with a thin coat of shortening before I cover them with fondant. I have never had any tearing issues, especially with Fondarific. If you use a base coat of shortening, I have heard you can soak the dummy in hot water after it’s useful life is over and the fondant will come right off. I haven’t tested that yet though.
Jenniffer White, Cup a Dee Cakes - http://cupadeecakes.blogspot.com