You should really tell people $686 a month or $552 with $3,500 down.
Or $636 a month or $552 with $2,250 down.
It doesn't say anywhere in your post you're asking for a down payment.
People are thinking, "Wow, what a great payment!" at $552. When really. . . Its about average. . . Especially with out 923 miles per month.
Good luck with sale.