for temporary installation just stick the (magnetic) antenna on the
outside upper "A" piller (or roof if passenger Vanagon) then open
open the door and run the wire into the van and across the dash.
Not elegant but it will work.

For permanent installation idea, search the archives.

>Where's the easiest place to run a satellite radio antenna wire to the
>outside (at least temporarily until I get home to my garage and can do
>it the right way)?