[niels44]

when there's nobody in the vehicle, pause it:
https://sampwiki.blast.hk/wiki/NPC:PauseRecordingPlayback

when someone enters the vehicle( as passenger ), resume it

https://sampwiki.blast.hk/wiki/NPC:ResumeRecordingPlayback

you could use OnPlayerStateChange for this, or OnPlayerEnterVehicle.

you could also reset the npc and the recording, if the person exits the vehicle again, while its still playing.

or a command like, /stopnpc, which will pause the recording, so the player can exit the vehicle.