The all-time record for a GNX was set in 2022 when a 568-mile car sold for $308,000, but the highest price paid over the past year was $255,000 for an 843-mile car.

It started with a Pontiac and a simple mission – break the 200 mph barrier and do it with a car buyers could order through a dealer. The result came years before Ferrari’s F40 reached its famous 201 ...