What's that little black thing on top of roof?

[Parthery]

Almost correct, they didn't bring out the shark fin antenna until 2006. But they did combine them in 2004.

That's odd...I had an '05 Denali that had one.

Was it a mid year production change?

 

[b4z]

Our 04 has two different antennas. It is stupid. I took the roof rack off and have these two zits to contend with now and I don't think that any vehicle before 2006 can get onstar because its not digital.

 

[Danzigman]

My '05 has both.