I am not sure about the 1988 but I was searching for an answer about a 2003 Seville STS and could not find information - So....I just tried with a Slim Jim i bought at a gun show and was able to unlock the drivers door in about 1 minute. The process was to insert the Slim Jim under the weather molding right in the bottom right side of the window. I inserted about 3.5-5 inchs of the tool down into the door frame and wiggled it around until it found the latch - i could tell i had the latch because when i moved the Slim Jim the look moved inside the door. with and upward thrust of about 10 punds It raised the locked door.
The fuel door release latch, on your Cadillac DTS, is located on the floor near the drivers seat. Pull the lever up and the fuel door will open.
Opening the driver door of a 2000 Cadillac Seville is easy. All you have do is pop off the door panel.
Use your key or electronic fob.
glove box
There isn't one. You simply tilt the door from the outside of the vehicle!
There is a pull pin release in the trunk
Push on the back of the door and it will pop open
Open the door with your key. Now pull the hood latch to open the hood.
I have a 2000 cadillac catera sometimes the radio will shut off when this occurs the fuel door will not open neither will the trunk
Pry bar and a hammer
I had the same problem with my 98 cadillac catera. I was told to manually open the door with the key and it should should off. Mine works on occasion. So when you go to open your door and the alarm goes off shut the door lock it and then unlock it manually again.
The one on top is to open the trunk. The one on the bottom is to open the fuel door.