Those brake lock things were good for a while. But now they sell online a thing called "The Club Buster." It was made for locksmiths and repo men, but of course any theif can order one. It looks like a big wing nut. It hooks to either a steering wheel lock or break lock and you just twist a knob and it snaps the lock in half.
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Found the link
http://www.clubbuster.com/clubbuster.htm