incidentally, i just got back from hong kong and there is a case to be made for this city as an ambient piece in its own right. certainly an influence on (or refraction of) the electric haze of vangelis ca. 1982, and more obviously the recent hk/asian inspired vapourware stuff.
the place is a mesh of sounds, a symphony of electronic pitter-patterings at street crossings going slow and fast and out of sync with the same sounds a block away, of zelda-like chinese traditional melodies issuing from (i suppose) cellphones and unseen electronic sources, an oddly soothing (and melancholy) melody filling part of yau ma tei station signalling a braille map of the station, the chatter and texture of cantonese (and central asian, and philippino) accents, the din of buses, the every-present sound of water brushing against the harbour. the whole is a rich, living tapestry of what can only be described as ambient.
the other very hk, very ambient thing i picked up was the buddha machine, a (now almost ten-years old) little box with pre-set loops by hongkonger christian viraant and beijing musician zhang jian. you turn the thing on and let it drone quietly as you do the dishes or whatever. it's like a minisucule hong kong generator that i appreciate very much as i plot my return to this wonderful (and troubled) place.
Obviously depends how you define ambient