After 5 years and 3 broken antennae's, I finally decided to solve the broken nylon mast issue. And since the repair kits are no longer available from GM, I had to. I bought steel cable from the hardware store about the same size as the nylon then welded it to the mast (much like the nylon) and to the curve and bent hook for the spool. I reassembled the casing with the mast fully extended, plugged in to car (i had already used a 3 prong connector there) and it coiled right up. Reinstalled and it works perfectly and should never break.
