if it's family:
you should sell for 45k, and consider any 'loss' as good will to family and an investment in your future happiness.
the reason I say this: your father in law should actually go call Tesla and get an inventory 75 with auto pilot, better battery chemistry, and overall better build for 73k minus federal EV tax credit = about 65k as long as he takes delivery by 9/30. (see the threads on end of q3 firesale).
on the other hand, maybe that's what you're doing...