Why does this guy want a bill of sale on this salvage vehicle?

I bought a car, a Buick, in 2007. I can not get a title for it. Long story.

In 2012 or so we gave it to Rick’s daughter as she drove for work a LOT, so she needed something that gets good gas mileage. Rick’s company provided him a car.

I really liked that car but apparently the transmission went out so she sold it to some guy for salvage for $100.

Well, she called last night and said he wants a bill of sale. Why would he need a bill of sale? If we were the ones selling it I don’t think we could come up with a bill of sale ourselves. (long story.)

He also wants proof that it has had insurance on it in the past.

What’s up with that?