There is a thread on this (or at least on the targa top). The targa top should be black eggshell/satin. I believe it was made that way so as to not show marring as it is handled and stored behind the seats.
Correct finish for both items is satin black. Often called 'trim black' one of the best sources is SEM that sells it in a rattle can.
Satin black Steve and you might want to consider putting a satin laquer on it as this finish is very easy to damage. I wish I'd thought to have satin laquer put on mine. Here is a photo of it. Image Unavailable, Please Login
On the 308 I know the wipers would be satin black but I'm not 100% sure how the Targa top was finished. I know there were variants over the years with some being smooth and others textured but GTS 308's I do not know as well as the GTB's