It was just my luck to find one in an Asian store a month ago. I'd never seen nor heard of it before... and when I tried it, I loved it. However, when I went back recently, they said they didn't know when they would get any more of them (no!!!).
After looking on the web, I realize there's different versions of the Nestle Aero bar (UK, Canada, Japan, etc), but hey, any or all of them would be great to find.