title states it, where is your navi antenna mounted?

Mine is on my trunk, and I hate it. I'm thinking of moving it by the third brake light, but not sure if it will work there...

I have a D3 BTW

 

Mine is under the rear window mounted on a round metal plate.

 

Mine used to be on the rear window outside corner on my last car. I don't know where I want to place the new one on this car. I know I don't want it on the outside

 

under the front windshield, by the vin number tag, works fine.

 

I believe alot of people mount them in the location of the factory gps antenna which is located behind the clock.

 

^ no issues reading through the plastic in the dash?

 

Nope. You may lose 0.5 dB gain, but there seems to be plenty of link margin. I have mine mounted underneath the plastic of the center brake lamp (sedan). It's completely invisible and resting on top of a steel base - perfect for the magnet to hold it securely.