Have a relative going to Scottsdale and it appears there are two GNX's going off with no reserve. One is #003? and appears to be the first car released by Buick. The second GNX #375, appears to be from the Corvette Museum. Will attempt to attach link.
https://www.barrett-jackson.com/Events/Event/Details/1987-BUICK-GRAND-NATIONAL-GNX-003-212343
https://www.barrett-jackson.com/Events/Event/Details/1987-BUICK-GNX-210275
https://www.barrett-jackson.com/Events/Event/Details/1987-BUICK-GRAND-NATIONAL-GNX-003-212343
https://www.barrett-jackson.com/Events/Event/Details/1987-BUICK-GNX-210275