For the final year of the Buick Grand National, 1987, Buick introduced the limited production GNX, for "Grand National Experimental", at $29,900. Made in partnership with McLaren Performance Technologies/ASC, Buick produced only 547 GNs with the interior trim package, that were then sent off to McLaren and upgraded into the Buick GNX. Buick underrated the GNX at 276 hp (280 PS; 206 kW) at 4400 rpm and a very substantial 360 lb⋅ft (488 N⋅m) at 3000 rpm of torque, although actual output is 300 bhp (304 PS; 224 kW) and 420 lb⋅ft (569 N⋅m). The stealthy appearance of the all-black GNX and Grand National (and the resemblance of its grill to his helmet's mouthpiece), coupled with the fact that the Grand National was initially released during the popularity of Star Wars movies, earned it the title "Darth Vader's Car".