OK, my CA just got back to me with a bulletin he received from BMWNA. I won't post it here because I don't know if it was intended for that purpose (probably it was, I'm just not sure). Regardless, I can give you US prospective purchasers the gist of it.
Unfortunately, BMW writes these things like they build their cars. Confusing. The bulletin definitely says Color HUD is included on 5 series and GTs for March production cars ordered with HUD (Option 610). That's fine. The problem is that an "extended display" will also be included with Option 610, but the only feature of this display mentioned is the extra width with more info. Nothing about black out when the car is off, gradually lighting up when you turn it on, etc. Further, the bulletin clearly states that if you PREVIOUSLY ORDERED A [PLAIN] 5 SERIES SEDAN WITH NAV THIS EXTENDED DISPLAY WAS ALREADY INCLUDED!
So let me ask those of you in the US who have NAV on your F10 535 or 550: do you have the extended display? Does it black out?
I told my CA, in effect, that if he wanted this deal to close soon he'd better get this straightened out.
HTH.