1998 Cadillac Seville Owner's Manual - Page 281

To open the fuel door, push the fuel release button located below the light controls under the instrument panel on the left-hand side. The vehicle mustbe in PARK (P) or NEUTRAL (N) and the valet lock switch must be off. An alternate fuel door release is located inside of the trunk on the left-hand side. Pull it to release the fuel door. f While refueling, hang the cap by the tether from the hook on the filler door. 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. 6-6