[JimD]

I don't know what the top speed of my sport package equipped 128i e88 but it is supposed to be 155 mph. I haven't gone near that. I drive with a GPS on all the time. It is on a metal bracket to the left of the gauge hood with the power coming up behind the gauges and out a slot in the back of the gauge hood. I have a backup camera that shows on the GPS screen. I see a 3 mph difference regardless of speed. I don't think it is a percentage, I think it is an offset.

I have also programmed the digital speedometer as an option at the bottom where you see instantaneous mpg. I eliminated the offset and it reads consistent with the GPS. That is just a couple commands to accomplish. Then you would not need the GPS. Your car knows how fast it is really going but BMW doesn't want to tell you. I think the stuff about the German law is nonsense. My car isn't in Germany. These are software settings. The speedometer should be accurate. Annoying but not a fatal issue for me.

Your speed cutout should be set no higher than your tire speed rating. I think you can change it with a programming change but I haven't done it.