I see what you mean. The fine point I was (also) trying to make, is that maybe the price we pay because of the already installed equipment does not cover the cost/ does not contribute to profit.

BMW may have chosen for 1 standard production line that always incorporates the heater and that the expected percentage of actual users who activate the system will create the profit.

Besides that, in my opinion, the system is not really different from buying a basic software package that already has all the functionality built-in, but if you want to use more functionality than is included in your basic package, you need to upgrade, i.e. buy a code to unlock the desired functionality.