I've uploaded a video showing my bugged state, here:
I have "completed" this quest already wherein I did all the steps necessary to complete it, including dropping the NPC into the car's trunk; I didn't notice the quest didn't actually complete, so I went on in my playthrough. It's been dozens of hours since then, so I am unable to revert to an old save where I did not have this quest.

Essentially, the NPC is not in the chair, the car is not waiting...

[Bug] Unable to complete Gig: Hot Merchandise