Random clunking noise at stoplight

Hi all,

I have a 2002 Acura RSX with about 125,000 miles, k20a3 engine.
I am hearing this random clunking noise coming from passenger side area and this only happens when all of the following are true:
- after I have driven for awhile (5mins+)
- when I am in drive (or reverse) gear
- headlights are on
- stopped at a red light.
- cold weather (not sure about warm weather since this is recent).

Any ideas what is causing this noise? And how I can check?

Thanks.