It is true that we don't need cars sending telemetry to track us since there is a conveniently placed identification number on the front and rear of the car, the number plate (used by government), but this is physically broadcasted and that limits its reach.

So why should the manufacturer of my car have access (and the right to sell) a lot of my personal data like location, weight, age indefinitely just because I own a product manufactured by them?

It is an unnecessary overreach on very sensitive data and I can't really opt out (if buying a modern car) since all manufacturers are doing it.

Yes I also carried a phone everywhere the last 20years, but that doesn't make the tracking right (also on phone I think we should be tracked less).

Speak for yourself. Also, lack of equivalent for "airplane mode" where it keeps functioning without remote connectivity makes it fundamentally worse.