Do interior mounted gps antennas offer better reception then exterior mounted antenna?

Yes. A digital TV antenna will give you better reception as compared to an analog TV antenna. But, a cable box or satellite dish will give you even better reception than a digital TV antenna.

Radio antennae are located in the rear side windows.

Behind the passenger side front fender.

If you want to change just the antenna it just unscrews. If you need to change the base I had to do it on my 99 vw beetle. At the back of the roof liner there is a plastic piece that comes off with a...

It is probably embedded in the rear window glass. In convertible models I believe it is inside the passenger door.