Dan, I don't have a Westy, but I use my antenna to warn me of low height
restrictions in parking garages. If yours does not reach above your pop
top, then, perhaps, you could attach some kind of "feeler" to the top. I
can envision some kind of wire devise mounted just above the drivers door
that you could lay flat until needed then flip up to warn that you are
getting too close.

Steve Wacker