[Flying Ace]

OP - That dealer is probably not lying to you. I have observed that in Europe, there are a lot of one-off one of a kind Individual colors made for many M cars. Dealers would order it and the car would sit on the showroom for close to a year sometimes more as the dealer would ask for a premium. It appears BMW allowed the dealers to have exclusive right to that color and may have excluded others in Europe from ordering the same color (at least in the same model year). Overall, the take rate in the M6 is also much lower than in the US, so any Individual color in Europe will be much more unique. I've seen this happen many times with M3s where a ton of very unique colors pop up in Europe every few months.

IMO, these colors are cool, but none of it is worth paying a premium for. What you may value as "exclusive" may not be what the next buyer may value. Ask yourself, why is this car STILL sitting there at the dealership and not sold if it's so damn "popular" or "in demand"?

btw, what color is it? I may be able to get some research on it and see how exclusive it really is.