I want to put my Nav Antenna inside the vehicle. Currently it's outside above the driver’s side front roof.

Two questions:

It's a 2003 Ford Explorer....where would be the best place to install it inside the vehicle towards the front?

And, if I need that tape that'sticky on one side with metal on the other to hold the Nav antenna in place, where can I purchase that from?..the installer who installed my Z1 must have throw mine away if the Z1 comes with that.

Don't have a Ford but can tell you that most vehicles have a metal beam somewhere under the dash going across.
Placing the antenna on that beam, preferably in the center, while making sure that there is nothing but plastic and glass above it, will give you top performance.
The antenna holds down with it's own magnet in that position. :)

I was also noticing on my Aviator...and your Explorer should be similar...that there was room for the antenna under the cowl between the hood and the windshield. There's plastic above it, so it should work fine there. Ducatiboy and I have our antennas under the dash. We mounted metal plates to the defroster ducting and let the magnetic antenna stick to those. Works extremely well there.

03Aviator said:

I was also noticing on my Aviator...and your Explorer should be similar...that there was room for the antenna under the cowl between the hood and the windshield. There's plastic above it, so it should work fine there. Ducatiboy and I have our antennas under the dash. We mounted metal plates to the defroster ducting and let the magnetic antenna stick to those. Works extremely well there.

where exactly is that defoster ducting? Under the drivers side, center?

On our cars, we found a perfect spot just to the side of the opening for the radio...up close to the windshield. Actually, there is a spot on either side. I put my GPS antenna on one side and my XM antenna on the other. Both work great!

03Aviator said:

On our cars, we found a perfect spot just to the side of the opening for the radio...up close to the windshield. Actually, there is a spot on either side. I put my GPS antenna on one side and my XM antenna on the other. Both work great!

so you did this with the Z1 out of the dash, right?

mine is already installed by an installer.

yes...it's under the dash pad and only accessible by removing the head unit...which is not a difficult job.