Well, I can't think of any other question better than this so
don't blame me if you don't know 
911 has 3 permanent S-Shift buses. 2 of them are Mercedes 0405
Hispano OACs and the other one is a Mercedes 0405G Hispano
Habit.
The Mercedes 0405G Hispano Habit is a ZF and is a spare (TIB1139K -
Answer by TIB1062Y)
One of the Mercedes 0405 Hispano serves 950
The other Mercedes 0405 Hispano has no perm service
I posted the answers somewhere before, so if you want you can dig
up the archives
