The 2004 Cadillac DeVille DTS is a moderately easy vehicle to maintain, but does have a few unique configurations that will take time to investigate. The components of the spare tire are easily accessible in the rear of the vehicle. This keeps the tire and jack kit ready to go in case of emergency. Changing the cabin air filter with reliability is no problem, as you only have to remove one easy to remove cover for access to the filter. The engine air filter is also easy to change. You only have to disengage a few fasteners for access.
Some things are problematic on the 2004 Cadillac DeVille DTS. You will have to completely remove the headlight housing for access to the bulb. This will require many tools in order to complete many steps. Checking the interior fuses will be tough, as you will have to move the back seat for access. The battery is located in the trunk. This is a more difficult to work in location than the usual battery location.
Hans Angermeier has produced over 100,000 videos showing drivers how to fix things on their cars. He has broad expertise on basic repair procedures covering the majority of cars on the road.