I just want to know if anyone has tried installing the antenna on top of the front or rear dash on the inside of the cab, I was thinking of painting the receiver a light brown (my interior color) and putting it as far back as possible so that it is where the back glass and the rear deck meet.. but wanted to know if anyone else has tried this.

And yes, I realize outside is optimal; Since I have sirius, I want to try and avoid having two antennas outside the car

I suppose it's an individual choice where the antennas go. I know the nav antenna is stronger than the satellite antenna. I've mounted the nav antenna under the dash near the surface and got great reception on another vehicle. I have both antennas next to each other in my present vehicle, sitting on the dash forward of the air vent in kind of a pocket. You can see them from outside if you look, though not as much inside. Do a test in the drive way before putting the HU back in. If you have a metal base tint on your glass this will effect the reception in the back window as well with the sirius anntena.

My GPS antenna is mounted on top of the metal support beam behind my instrument cluster. I've always installed GPS antennas there and never had any problems with reception. As long as there is no metal in the dash skin on top of them they'll work perfectly and be completely hidden.

thats what I needed to know, ty