What flag is this?
I saw this flag as a sticker on a car from another country. I could not recognize the plate so I do not know its nationality.
My search on Google/images resulted mostly in the Madrid flag...
...and the ECSC flag.
But those are certainly not correct. I write from Spain and I have never seen a variant of the Madrid flag such as this, neither official nor unofficial.
The image I offer is not a photo, but a "reconstruction" made by me with MS Paint, but I am pretty sure that it is faithful in colors and in the number of stars and their position.
(I edit to add some clues on the license plate)
I've been looking for Middle-Eastern and North-African plates, because of the crescent moon on the flag, and I'm quite sure this was not an Arabic plate. Plates in most Muslim countries usually include Arabic numerals and letters, like this one:
European plates usually consist of black numbers on a white background and "no frills". But this flag had a comparatively colorful background, green, blue, like a bank note. It's possible that it was a plate from the USA, like this one:
Important CAVEAT: I couldn't see any flower, nor the name of the state. I'm not saying that it was an American plate. But it had green, blue and white colors which made it look like a banknote.