Another thing to consider if your planning to dash mount the scanner.
Where are the air bags located in relation to you installation.
Thats why I started doing the in-dash installation. As shown in photo
next to my user name.
As mentioned by ka3iiz, the in-dash installtion makes the scanner
less obvious and appear to be too much trouble to try and steal.
Plus no holes in the dash.
However; if you decide on in-dash, I would go to an auto-recycler and
pick up a second dash bizel. Do your modifcations to it thus, when time
comes to replace the vehicle you can put the orginal dash bizel in and leave
no trace of the scanner.
As for antennas, I used glass mount, mag mount and am/fm spliters.
and work will, The spliter does help to make the "extra" radio
less obvious, the downside is some internal "birdies" from the car.
Less interfernce with the glass mount and if done right can be removed
without a tray, when time comes to trade the vehicle.
Currently I'm using a small mag mount that is not as noticable as some.
Check my thread further down the list, Dodge Chager Installon for photos
of the mag mount..