finally solved this... collected my car on Monday late noon.
The rattling noise is gone. Its actually comes from the seatbelt mechanism on driver side B pillar; behind the plastic housings. Phew!
However, i would like to share that this particular Toyota Balakong SC is not recommended if you plan to leave your car there for some time. After i collected my car:
1. Got thick grease stain on my car seat, and B pillar body.
2. Some kind of liquid on my car mat on rear seat
3. Scratches all over my plastic housing that covers the B pillar; and door panels after they fiddle around with
4. My fuel tank becomes EMPTY; whereby my ODO trip meters at 290km only. My average mileage per tank is around 400. When i send in my car, it was around 210km.
5. My total ODO was around 58xx, when i got my car; its at 59xx. I highly suspected that they drive my car around and thrash it.
6. Sweet liquid(like Teh or Milo) stain on my cabin; especially the centre console cover.
I wonder if i could bang table at their Manager office.
I'm so pissed off now.
Should also complain to the Service Advisor on the spot when you take ur car and take photos of the problem that you have mentioned above as proof.
Perhaps Toyota should compensate you with free service or other things for ur inconvenience.