The right way to sell subscriptions is for services that actually incur ongoing costs for the company. Charging a subscription for hardware and software already built into the car, and not dependent on any external servers or anything is just plain anti-consumer. There are plenty of services BMW can charge for that people will happily pay, like remote start, remote monitoring etc.
Step two: Charge subscription fee to get paid to finish developing product
Step three: Add useless features and do confusing redesigns to justify subscriptions
Step four: "Subscriptions are necessary to cover ongoing costs"