In most states, you CAN claim an abandoned vehicle but only if it's on your property. So the side of the highway doesn't count.
If he doesn't even have the cash to have his car towed, offer him $100 for it and I'm sure he'll take it. He doesn't have any other options.
'97 E300 Diesel (daily driver)
'87 Porsche 911 (track car)
'02 Porsche 911 (weekend toy)