One really good reason for a speedo to show a top kmph far higher than is legal, is that the meter should always be able to show the actual speed the car is going, and therefore needs to have a maximum of the maximum speed of the car.

It's the only good reason I've heard.

On that we could do one of the following:

• Speed limit the car, then change the speedo to max
• Include the regular dial type speedo up to 130kmphish, then a digital one for any speed above that.
• Change the speedo so that the dial moves a long way for slow speeds, moving toward not moving very far at higher speeds.

I don't really like the idea of speed limiting the car, I think I like the last option better, but it isn't a new idea. They also argue that you probably don't want the speedo to be deliberately less accurate at higher speeds.

Problem number one... car makers don't have to have accurate speedos, so they don't.