I have seen a few 07's with the roof "shark fin". What models come with this? Part of the tech package?

That's the XM radio antenna. It comes with any model that's equipped with XM.

Why did you post this thread twice?

Ha Ha. The better question is why post it in the picture share?

If the car isn't equiped with XM, but you get it dealer installed, what process takes place? Is it a simple plug and play in the trunk with an antenea mount or do they have to take out the head unit, headliner etc. to run the whole deal?

you can find that here

http://www.infinitihelp.com/Ownershi.../ITB06-019.htm

I had a brain fart and didn't notice I was in the picture thread with the 1st post.