Implementations relate to enabling of authorization of certain automated assistant functions via one or more modalities available within a vehicle. Implementations can eliminate wasting of computational and communication resources by at least allowing other users to authorize execution of certain input commands from a user, without requesting the user to re-submit the commands. The vehicle can include a computing device that provides access to restricted data, which can be accessed in order for an action to be performed by the automated assistant. However, when a restricted user requests that the automated assistant perform an action involving accessing the restricted data, the automated assistant can be authorized or unauthorized to proceed with fulfilling the request via a modality controlled by an unrestricted user. The unrestricted user can also cause contextual restrictions to be established for limiting functionality of the automated assistant during a trip, for certain types of requests, and/or for certain passengers.