here is what i did. I did it this way so as to avoid drilling unnecessary
holes in my bus:

i removed a tie-down loop from the luggage rack on my westy and sandwiched
a piece of metal between the fiberglass and tie down. This metal has a
hole in it similar to option #3. I then snaked the wire through a drain
hole in the luggage rack to the front window of the pop top to the inside
of teh bus. Works great. I leave the antenna off except on road trips and
logging roads (where it is mandatory).

Matthew Pollard          "Racing with the wind and flirting with death
Dept. Of Chemistry        So have a cup of coffee and catch your breath"
University of Idaho
www.uidaho.edu/~poll7356
>
> 3 - harder yet, 1 hole, cheap.  Drill a hole through the luggage carrier, and
> through the metal roof of the cab.  Install a 3/8 inch mount from Radio Shack.
> This is a real pain, but doable.  I did mine dead center, but you do them
> anyplace, and do several if running VHF/UHF/microwave verticals.
>