In this case it's not really clear that they're adding it to all cars. In all likelihood if the subscription scheme exists (which there's also no clear evidence that it is), you'd have to opt in to the expensive tires first.

And if e.g. those extra costs are 15 cents then the only reasonable extra charge is 15 cents?

It’s not free to do pretty much anything, even sending a single HTTP request, so curious how you calibrate.

Easiest calibration: if the feature is already present to the client, requires ONLY pushing a secret button or sending a special one time request, but doesn't require any ongoing http requests or unpaid maintenance on provider side, then it should be free. Like cabin heating or snow chain deployers.

So if you have a mass-produced product and you want some variable features available for customers’ different preferences and price points, you ought to have different manufacturing processes even if you can actually create that variation in software? That seems very wasteful IMO.

If it's cheaper to include hardware in all models than to make different hardware versions, that sounds like you shouldn't make users pay more for actually using the hardware that is already there.