[thstone]

As far as I am aware, there is no particular reason to wrap the cat delete pipes. The stock cat pipes are not wrapped and there is sufficient heat shielding under the car. All of the pipes that I have seen (along with the primary cat delete pipes on my Spec Boxster) are not wrapped.

On the other hand, I am not aware of any particular reason not to wrap them if you wanted to try and cut down the radiated heat around the engine area.