I put the antenna for my starmate inside the car on the rear deck. No problems with reception, easy to thread wire, and no little black bump on the outside of the car. BTW with a little creative wiring, (go on the passenger side) you can mount the head unit in the little cubby hole under the radio at the front of the console. Then you can close the lid when you park the car, and no one can see the radio.

I used the base of a cheap picture frame and some velcro to make a bracket to hold the radio. I ROCK!!!