...expect Phil's inner pedant to show up any day now to point out that, technically, "Down Under" is a noun phrase rather than a pair of prepositions.

Well, at first I was going to suggest that "down" isn't a preposition, but changed my mind. Both my inner and outer pedants are happily turning a blind eye to the capital letters of "Down" and "Under" too :)

(Phil) I didn't want to arouse the Wrath of Dujon or that of any other Strines.
(CdM) Course it's a noun phrase, my exopedant tells me. The medial- and endo- backups needed no invoking.

The Wrath of Dujon sounds like a title of a Doctor Who from the early Pertwee era. :-)

[CdM] I like it, hope they recover the tapes one day. Or it might have been a working title for the second Star Trek movie...
Kirk: "Duuuuuuuujonnnnnn!"