In addition to wireless communication interfaces that are relevant or immediately apparent to users (such as Bluetooth or WLAN), many internal vehicle systems communicate directly with the manufacturer's IT systems via integrated mobile radio interfaces. Users typically cannot influence this exchange of information. This includes not only systems that are prescribed by law and transparent to the user (such as eCall), but also those that are not immediately apparent to the user. For example, many vehicle manufacturers collect detailed information about the location and mileage of a given vehicle or about the driver's behaviour. This could result in extensive personal data being aggregated on vehicle users without their knowledge or explicit consent to this data collection and processing.

Insecure vehicle communication interfaces represent a further threat. A lack of protective mechanisms in this regard can allow access to sensitive data. If, for example, an infotainment system allows Bluetooth pairing without security mechanisms, an unauthorised third party could pair their smartphone with it and synchronise address books without anyone noticing.