Answer
The 7 series and m6 arent specialty cars. the m3 gtr is a specialty car. the 7 series was the flagship before the m6 came back and took its place. flagship cars are the most expensive cars a brand offers (not including specialty cars) specialty cars are limited edition cars that have undergone extensive factory modification. the 7 series is completely unmodified, and the m6 has the standard "m treatment" (same type of modifications as all other m cars) and thus cannot be counted as a specialty car.