What if a customer ordered a car without the multifunction steering wheel and BMW accidentally built it with it. Couple of years forwards and someone notices that for some reason, the order sheet and the build sheet do not match. The owner takes their car to be serviced and the BMW technician switches the multifunction steering wheel panel with the blank steering wheel panel.
How can BMW at that point explain that the customer never paid for cruise control and therefore they never had it? The manufacturer shouldn't punish the consumer for their mistakes.
This is like them saying "Oh, we forgot to charge your dealer you for the premium interior and lighting" (which is listed on the same sheet as a $5000 option) - your response would quite rightly be "Tough, I bought it from the dealer at the agreed price based on the features listed, it's mine now"