According to
AMuS (I used Google Translate so forgive me if there are mistakes):
-Both Mercedes drivers will run the new aero parts in FP1 at Suzuka.
-According to their wind tunnel numbers the new updates are worth at least a tenth of a second.
-They are worried about the weather prediction, Friday practice sessions are mainly going to be on a wet track, qualifying will be dry, but cool and there will be a significant raise in temperature on Sunday.
-If they're going to have any problem, it's gonna be visible on Saturday (the car has to be prepared for completely different conditions on Sunday). And Suzuka's asphalt surface which is very rough with a lot of grip is going to be problematic as well since their car requires the opposite of that to perform well.
"A fool thinks himself to be wise, but a wise man knows himself to be a fool."~William Shakespeare