FWIW, there are some things, mostly related to the subject in hand, that you can download and update in your car by yourself. Check the BMW website. You'll need to generate a login as a user, and put in your VIN. It will list if there are any of those updates available for your car.
Basically, BMW won't let you update core, operational software, but for things like entertainment and integration of phones, those functions sometimes are available for the user to update. You can update your maps by yourself, but not the underlying operational software, for example. You can often find the maps for your car online, and might need a code that you'll have to purchase to get them installed, but the data is free. If you pay a dealer to do this for you, they'll charge anywhere from about a hundred to three.
