OK, here's a tough one. The rubber/foam part of my XM/Onstar antenna (shark fin) has broken in half. Went to the dealer to buy a new one. He brings out a replacement that looks similar but it just twists in place. Mine is attached to the base with two small torx screws. He says they must have changed the design mid-year. His book doesn't even show mine. I would have to buy a new base that accepts the new twist-on antenna. And it looks like the base is removed from under the roof, above the head liner. I have an 05 H2. We even checked the 04 model to see if maybe my style was listed but that antenna is totally different. Any suggestions? Thanks.

 

I know this is a old post, but maybe some will be looking jut as I was for this antenna. P/N 20842596. Check E-Bay priced as low as $18.00 to $40.00. Just unscrew broken antenna and screw in new one. No need to remove the base.

 

This is the version I mentioned in my original post. This does NOT fit my H2. It is the twist style. These are available everywhere. Amazon, the dealer, ebay, etc.

 

Just bought a 2005 H2 have the same problem with the antenna did you got the right antenna

 

No never did. Had to rebuild mine using bonding putty.