When ACC is engaged on a specific speed (faster than the speed limit), but the car is driving slower for example because of a slower car in front of you and I engage AP, AP is engaged but the speed limit is changed to the current speed. This is really annoying because I then have to update the desired speed. I can imagine that using the current speed is taken when AP is engaged when driving manually, but if ACC is already used this doesn't make sense.
Idea No. 1003