  Due to the increasing connectivity of modern vehicles, collected data is no
longer only stored in the vehicle itself but also transmitted to car
manufacturers and vehicle assistant apps. This development opens up new
possibilities for digital forensics in criminal investigations involving modern
vehicles. This paper deals with the digital forensic analysis of vehicle
assistant apps of eight car manufacturers. We reconstruct the driver's
activities based on the data stored on the smartphones and in the
manufacturer's backend.
  For this purpose, data of the Android and iOS apps of the car manufacturers
Audi, BMW, Ford, Mercedes, Opel, Seat, Tesla, and Volkswagen were extracted
from the smartphone and examined using digital forensic methods in accordance
with lawful government-approved forensics guidelines. Additionally,
manufacturer data was retrieved using Subject Access Requests. Using the
extensive data gathered, we successfully reconstruct trips and refueling
processes, determine parking positions and duration, and track the locking and
unlocking of the vehicle.
  These findings show that the digital forensic investigation of smartphone
applications is a useful addition to vehicle forensics and should therefore be
taken into account in the strategic preparation of future digital forensic
investigations.
