Where are the spark plugs located on Cadillac DTS 2003 on 2003 Cadillac DeVille DTS

Thinking of changing them

Asked by for the 2003 Cadillac DeVille DTS
They should be under the engine cover. I found this which should help you. It may not look familiar because they used a coilover coil pack on your car. Basically instead of a central coil pack with plug wires running to the plugs, there is a plastic thing with a short boot on the bottom. you probably wont even see the boot until you remove the coilover. This pic should give you a better idea of the assembly.
it is easy to do the front but a tight squeeze to get to the back. Good luck.