When you choose a car and you can select the skin, It would be awesome if you could add lights with a colour of your choice.

It's already possible,but you have to buy S2 licence for that!
(as you know - marketing is based on lies anyway...)

I'd like head lamp washers. Hate it when they become all dusty on the rallycross tracks.

No need for a special key, just the same key for the windshield washer/wipers could be used for the headlamp washers.