Porsche GT3
 

Please can somebody tell me what the difference is between the "new" GT3 and the previous 996 version?

In a nutshell, more power and a different spoiler.

In this moth's EVO they drive them both and the older version is preferred. all a bit academic to me, unfortunately.

:)

Track is greater, and I think it has ceramic brake disks (PCCB).

Evo preferred the pre-facelift one as it is supposed to turn it a bit better.
I believe the additional power is almost offset by additional weight

Correct about turn in, but the new one has the ceramic brakes as an option (6k option!)

up to 381 brake from 360, got lighter engine internals. all round better engine

It is also facelifted so the fronts squarer and it has the new look headlights (or old and new turbo headlights)

different wheels