2017 Hyundai Elantra Multimedia display Clock hasn't worked since oil change at dealer

SOURCE: oil change procedure on a 2005 Hyundai elantra

it is very easy to change the oil put the car on ramps secure the back end look for the drain plug underneath the engine make sure you have the right size wrench and when you remove the plug also check the gasket on the plug to make sure it is not cracked you will also need an oil filter wrench and my other suggestion to you is to go to autozone to see if they have a Haynes repair manual for your car and if they don't see if they can order you one in the mean time they can also print you off a diagram of how to change the oil in you car safely

SOURCE: location of oil filter on a 2008 hyundai elantra

It is located under the alternator. If you are looking down at the engine, it is to the far left. If you are under the car it is to the far right before the oil pan.

SOURCE: Hydraulic arms for 2001 hyundai elantra hatchback

Take it back to the dealership and tell them to FIX IT!

SOURCE: change tke hood realase cable in hyundai elantra

Service and Repair Notes HOOD LATCH CABLE REPLACEMENT Remove the following items: Hood release handle. Radiator guard. Hood latch. Wheel guard. Using a clip remover, detach the clips from the body, then remove the hood latch cable (A) from the vehicle. NOTE: Take care not to bend the cable. Installation is the reverse of removal. NOTE: Make sure the hood latch cable is connected properly. Replace any damaged clips.

SOURCE: How many quarts of oil will the 2008 Hyundai Elantra hold?

Does the book say 6 quarts? I would put in 5, then run it, then let it settle for a couple minutes, then check it again. The book should be right. That would probably include changing the filter also.