The draft of this bill states, "PROHIBITION.—It shall be unlawful for any person to access, without authorization, an electronic control unit or critical system of a motor vehicle, or other system containing driving data for such motor vehicle, either wirelessly or through a wired connection."
IANAL and this is not legal advice. My reading of this makes me believe that if I own a vehicle and am not legally precluded from accessing data due to another law such as DMCA then this law would not preclude me from accessing the data. As the owner I would be the one whom authorizes accessing the data. If I buy a computer from Dell running Windows I don't have to get authorization from Dell or Microsoft to access data on or created by that computer.