1987 was the last year the Grand National was produced, and as a fare-well car both to the performance icon and to rear wheel drive cars, GM created what is easily one of its greatest cars of all time: The 1987 Buick GNX. Only 547 GNXs were made, and they were all absolute monsters. Every single piece of these cars was optimized, and as a result it was easily one of the fastest things money could buy. That said, $29,900 was a lot of money to spend on a car in '87.
Buick's official specs for the car were that it made 276hp and 360 lb-ft of torque, which pushed it to 60mph in 5.7 seconds and did a quarter mile in 14 seconds. The only faster accelerating car was the Lamborghini Countach. When the press tested the GNX they soon realized that something wasn't quite right: on the dyno the GNX proved to make 300hp and an insane 400 lb-ft of torque and on the drag strip it did 0-60 in a scant 4.5 seconds and did the quarter mile in only 13.26 seconds. GM lied to protect the Corvette's image. To put that kind of speed in perspective, a 2013 Porsche Cayman S goes from a stand-still to 60mph in 4.7 seconds.