CHEVROLET 1999 Corvette - Manual (Page 257)

yellow blue
6-7
If your fuel filler door release won’t operate, there is a
manual release tab. The tab is located against the upper
trim on the driver’s side in the rear compartment. While refueling, place the cap in the holder on the fuel
filler door to prevent damage to your vehicle’s finish.
To remove the cap, turn it slowly to the left
(counterclockwise). The cap has a spring in it; if you let
go of the cap too soon, it will spring back to the right.