Originally Posted by bmw-man-uk
i test drove a 525 and the speed limit on that showed the last speed caught even when it was parked up. id be interested in knowing if it shows national speed limit sign
If by "national speed limit sign" you mean the black diagonal stripe on a white disc, the answer is no; it just displays the number 70 on white within a red circle, as per all other limits.
After four months, I still occasionally find it indicating the wrong limit; therefore, I never rely on it. TBH I think it's more of a gimmick and I won't order it on my next car.