1 in about 1,000,000 people nowadays will stop to help when these kind of things happen.
noone wants to waste their time or be involved or get in trouble.
the best thing they could of done, and probably the most legal thing would have been to call the cops, and get rego plate details.
if it was family or friends in trouble i would have done the most i could but if it was something like this and i didnt know anyone i would have called the cops and/or followed the people home or where ever they were going to let the police know.
really sorry to hear about your car and your family. i knew the car when the first owner who built it had it.
goodluck with all of this mess.