It's a real song. It can be found on Rebecca Pan's 4 disc 101 song compilation. There are two renditions of the song on the last disc. The lyrics from the booklet:

Kowloon, Kowloon Hong Kong,
We Like Hong Kong, That's the Place for You.
Kowloon, Kowloon Hong Kong,
We Like Hong Kong, That's the Place for You.
Walking Down the Street, Full of Joy,
Come Here, Come Here, Rickshaw Boy.
Take Me Down the Street.
Chop Chop Chop.
"Howbar, Howbar, Joe" (?)
"Dinghow, Dinghow"
Kowloon, Kowloon Hong Kong.
We Like Hong Kong, That's the Place for You.
That's the Place for You.

http://us.yesasia.com/en/PrdDept.aspx/p ... ion-music/

The actual Rebecca Pan version of "Kowloon Hong Kong" can be heard in the opening moments of GOLDEN CHICKEN 2, as the Hong Kong of today morphs into the Hong Kong of 2046 via digital effects - a great moment. It is also on the soundtrack CD, which, like its predecessor, has a fantastic cross-section of Hong Kong pop music both new and old. This CD is also available at YesAsia and will likely cost less than the Rebecca Pan set if you're just looking to get that song.

Brian, thanks for pointing that out, I don't remember it from GC2 but now I do remember you previously mentioning that you liked the OST.

I don't recall what I paid for the 4 disc set but I think I got it for considerably less than what it's currently going for.