and neglect to include an offline requirement

Oh the innocence. Execs don’t neglect that, they specifically ask for that. This bed doesn’t work without a subscription so offline functionality would lose them money

as cars always show higher than actual speed

Although that is true, your car is quite extreme in that regard. In Germany cars are not allowed to deviate by more than 3kph at speeds below 100, and 3% at speeds above 100. I doubt BMW uses different speedometer for cars sold in foreign countries so I’m pretty sure there is something wrong with yours. Maybe you installed smaller diameter tires than from factory?

That’s exactly how they work in Mercedes cars

Yeah, anyone that has ever used Hackintosh, especially on a Laptop, knows that MacOS is much less resource intensive than Windows