… the profit margin is 100% no?

Whoops, you're right, I meant markup instead of margin. Fixed now. (For the curious, margin is (revenue-cost)/revenue, and markup is (revenue-cost)/cost.)

Why is the cost zero? They have to cover the cost of making the car.

The cost to them of the owner of the car using the heated seats is zero. The cost of making the car doesn't get used here because that would be double-counting it, since it was already counted in how profitable the sale of the car was.

They have to pay to put the heater into the car in the first place.

But since they paid that even if the owner never uses the heated seats and so never subscribes, it should be counted against the sale price of the vehicle itself and not against the subscription.

> it should be counted against the sale price of the vehicle itself

But why? Why should they do that?

For example a band that plays a concert counts on extras like merchandise sales to cover costs. Should the ticket price cover all their costs and is it unethical to also offer merchandise if they need it to cover costs?

I can't understand the logic in this thread.

The part of giving drivers heated seats that actually costs the manufacturer money is the seat heater hardware, which is part of the vehicles that are wholly sold.

Concert merchandise is fine because it has a cost that they only incur for people who actually buy it. For your concert example to be a valid comparison, imagine that everyone who bought a ticket to the concert were given merchandise, but told they weren't allowed to use it and had to throw it away when they got home unless they paid for it.

> The part of giving drivers heated seats that actually costs the manufacturer money is the seat heater hardware, which is part of the vehicles that are wholly sold.

And they’re recovering that cost and making some profit with these subscriptions.