Exhaust Wrap?

If I put a new Y-pipe and cat-back exhaust on my 03, would it be a good idea to put exhaust wrap around it and how far toward the rear should I go?

I put exhaust wrap around the flex section of the Y-pipe to try to eliminate the retarded rattling sound...it didn't work to well. The best place you can put exhaust wrap is around the headers, but that takes some real blood sweat and tears...it will decrease underhood temps dramatically though.

I will have the new Y-pipe and back off the car very soon I was just wondering if I should wrap anything before it is on the vehicle. I am using the stock headers and that seems like a lot of sweat wrapping those. Does anyone think it is worth wrapping the headers or is that just for more powerful engines?