Earlier quoted context omitted.
I noticed this ~5KM/H difference between my GPS and the speedometer of a Toyota 2014 model. I checked and it had to do with liability apparently[1] https://www.reddit.com/r/CarsAustralia/comments/10d4g0b/spee...
It has always been common for cars to estimate your speed a bit on the high side, because there's always a margin of error, and that way you don't accidentally go over the speed limit while thinking you're still below it. But for a car to start beeping (or worse, interfering), they'd better use that margin of error in the other direction.
How we allow massive touch screens in Tesla's and other modern cars is beyond me.