do i need to get a document from immigration showing my residency address for a car registration RENEWAL? for new registrations yes, but i forget if each year i need this for renewals..?

I'm not sure what you mean by 'registration renewal'? Once registered, the only thing you have to do is to go to the land transport department to pay road taxes on the car each year. That does not require a residency document. I've never had to show anything except the blue book and the payment, and in my case of a car over 7 years old, a road worthiness checkup clearance.

You now need the compulsary government insurance certificate as well, that plus your blue book and cash is all that is required.

You now need the compulsary government insurance certificate as well, that plus your blue book and cash is all that is required.

Good point JohnC, I'd forgotten about that updated requirement.