you could offer the family you take 1500.00 of the sell price, to clean and upgrade the car to ebay high selling standards, they pay for any parts the car needs, you clean and list the car for them, and sell it for them.
odds are good the family will not want the hassle of dealing with a mechanic repairing the car and make you an offer for you to buy the car.
the car will sell much better from the ORIGINAL owner than from someone fixing up a car bought from the original owner, but it'll still sell very well online.
I imagine Tyler could flip this in great style.

I could not in good conscience attempt to low ball a family car from someone.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!