That Roku is registered to someone else's Roku user account. They should have wiped it before selling the vehicle, but you need to do that and link it to your own account. You can do a factory reset from within the Settings/System menu, or you can press and hold the hidden reset button for 30 seconds. The menu option is easier. But if that PIN blocks you from doing a factory reset, the hidden button will still allow you to reset the Roku.
Dan
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee, just another user.