Just picked up an 05. First one. There is no antenna and looking in the hole there is no threads in the hole where the antenna would thread in. It's smooth. Anyway, looking at replacement bases, there appears to be a rod sticking out. See picture below. But all the replacement antenna rods show them to screw in. So I have a hole with no threads, replacement base shows an exterior rod, but replacement antenna rods show them to thread in. What am I missing!???

 

My guess is that rod is threaded on the inside. There will be an adapter stud (or should be) if you buy a shorty antenna....not sure if you buy just a replacement antenna. That stud would screw into that base and threads would stick up out of the base cover that the antenna would screw onto. Not 100% sure, but that would be my guess.

 

Check out AmericanMuscle.com They have shorty antennas with the threaded stud pre-installed for 13 bucks shipped.....not sure if you can beat that!
http://www.americanmuscle.com/8inch-...enna-0509.html

 

The hole in the antenna base on the car is smooth. Adapter threads won't work as there are no threads in the base to thread an adapter plug/rod into. It doesn't appear stripped and the walls are smooth????

 

that may be just a filler piece to prevent stuff from getting trapped in the threaded hole for the antenna.

 

Sounds like the base is broken. Post up a picture of the base, as this will allow us to help you better.

I just looked at my antenna base on my 05. The first 1/2 inch of the antenna mounting hole is smooth and un-threaded. If you look down the hole with a light you should see threads down in there. If you do not, I would suspect someone tried to remove the antenna and the threaded portion of it is broken off and still in there. In that case you will need to replace the base.