The ZR-1 "goes fast better" (Car and Driver, 1991). For the 1991 model year, GM adopted the motto 'if it ain't broke, don't fix it', and left the Corvette largely unchanged. Base models started wearing body panels similar to the ZR-1, and wraparound parking/fog lights became standard on all models. The 1991 model also incorporated a delayed auto-shut off the electrical systems powering the stereo and power windows. This feature continued to deliver power to these features after the engine was turned off until the door was opened or until 15 minutes elapsed.
With the advent of the ZR-1 in 1990, orders for the Callaway twin-turbo (RPO B2K) declined. In the first few years, sales for this option exceeded 100. By 1991, only 71 people had their Corvettes sent to Callaway to have the engine modifications made.
If you buy a Corvette from 1984-91, the chances are that you'll see a fair amount of red cars. Chevrolet offered two versions of red for these years (Bright Red and Dark Red Metallic), and over one-third of the 250,503 Corvettes produced during the 84-91 period were painted one of these two shades.