Fact find.
The feel of the wheel makes the deal. They all must test drive
Why are they in the market for that particular make/model?
What one thing caught their eye on your particular car?
Have they looked for others like it?
How many prior? And what other makes?
What do they like the most on your car/offer?
If there's one thing from buying, what would that be?
2 other guys came by and looked at it. One is very serious.
There's more, but maybe some of these can help you.
Keep enthusiastic and act proud of the car. Most of all, build value.