Okay, I ordered the plain FRP 240z tail light surrounds and the cowling that sits behind the bonnet. I'm not a carbon *****, so FRP was fine for me.
The tail light surrounds are incredibly well made, thin - 1.5 to 3mm thick depending which part of the piece is being looked at. Very uniform, stiff, no thin spots.
As for weight...well one surround is 157 grams! So for both left and right you're looking about 315 grams.
The last photo is of the back of the piece.
Now for the cowl piece - again, FRP, weighs in at 1290 grams, not sure how much lighter than the steel piece it is, but it is certainly lighter!
Back side of the piece
Very stiff piece, with all the proper molding points molded i.e. the tabs that sit beneath the screen, the same goes for the lip that sits under the lip of the bonnet, all holes drilled. You can see in the photos where they've taken the time to grind back the fibreglass to form the vents properly. The odd pin hole in the paint, but it's not meant to be a final paint layer, just helps as a stopper. Very happy with the pieces!
Hope this helps some of you if you're unsure, all I can say is PLEASE show some interest so Retrospec will do some fibreglass fenders!