Suggested

Yas Marina at night

How simple is it to switch a backdrop on a track? Since Yas Marina is now a night circuit could we ramp it to that?

Fun suggestion but remember that chances are if you’re racing at say 16:00 European time, that’s probably the night in say, Australia. 

But in the Singapore race isn’t the time always night in the scenery?

yeah and 16:00 for Europeans would be 10:00 for me

Perhaps you've missed my point or I'm misreading you... F1 race time of day isn't going to be the same as iGP due to various time differences, while iGP calendar doesn't modify start times. 

Also, Singapore is strictly a night race; AD starts while the sun is still up.

I guess most people remember Yas Marina as a night race though because it always ends in all the iconic photos are taken at night. I just think switching the scenery to a night scene would be better fitting for this track right now

Yes,maybe it can be good,will be more interesting with more night racing