Uh, Guys?
The air recognition symbol for medical vehicles IS the red cross. My bet is that is exactly what is painted on the windshield cover.
By the by, I was teaching law of armed conflict and international humanitarian law in Africa recently and the new red crystal (
http://www.icrc.org/web/eng/siteeng0...7?opendocument) came into effect on 14 Jan 07. Thus adding it to the list of international emblems representing medical establishments and units: red cross, crescent, lion, sun and crystal.

Mike