Only by upgrading to the MMI navigation system do you get access to the app store. From there, Audi forces you into add-ons like adaptive cruise control or Apple CarPlay and Android Auto for a one-month, six-month, one-year, or three-year subscription. Or you can just purchase any of those features permanently—although Audi doesn't say for how much.
Sounds like you’re right, but people are still right to be wary of this scheme, as the additional market segmentation will likely push up the cost of buying the feature outright. Audi is incentivized to push as many people toward the subscription model as possible to decrease the value of used vehicles.