"He says he could be here by around 10pm but again, trying to be decent, I tell him that it would probably be better if he saw it in the daylight" Why would the seller give him that option?
Maybe to insure all the trim or items that were included are present. Ever try to sort through stuff like that in the dark? BTDT and not fun.
I don't look at as giving the buyer an option at all and prefer to do deal in the daylight, during generally accepted business hours. As anyone knows, some areas aren't real safe. Have two vehicles towing trailers, one with out of state plates, pull into a parking lot to transfer a car late at night, you're asking for trouble from the local hoods or the PD.
The car could have been sold to two individuals I knew for at or very near full price, but, were told a deal was struck and a deposit had either been received or was forthcoming. They found other cars since then.