The one thing that comes to my mind are the aluminium bulkhead mounts, but there may be more.
Edit: F2 body, Ti coated shock shafts, aluminium servo mounts, graphite arms, front wing
I wonder if the world car didn't have more carbon/graphite parts like castor and front hubs.
Got the aluminium chassis baces too (top plate mounts), an expensive option.
What I liked about the original YZ2 (and the CA to some extend) was the fully equiped car out of the box for astro/carpet and I seem to find that in the CA2 plus lots of little improvements here and there.
Like it !