[nascarnation]

I don’t understand your post.
Why would I want the vehicle computer out of some other random car?
It’s immediately going to spit fault codes because the VIN is incorrect.

[ZOOKER]

How could a computer read the VIN plate under your windshield?
How would it know it's been installed in a different car?

I know, there are practical hurdles to consider - different cars, different makers, different engines, different options - won't swap. But I can dream, can't I? You won't get the car makers to stop installing them, and you won't get the gov't to stop accessing them. Disabling them only draws attention and is probably illegal. Let's find a way to make the data useless.

[SpeakerToAnimals]

It’s immediately going to spit fault codes because the VIN is incorrect.

There probably is not a discreet black box. It will be software spread across multiple systems. Just as an example, the ABS/TRAC ECM receives speed data from each wheel sensor. Then it passes it along to the Powertrain Control Module, then over the CAN bus to the dash computer to drive the speedometer. Nothing stands alone in a 21st century car.