You can follow this website on how to clean your care and bring back the shine.
In the video he suggests to use dish detergent to remove any wax on the car and start from scratch by using compounds. Then you will apply wax as needed. Dish soap is only used in cases that you want to remove the wax build up and get to the paint to better remove the swirl marks. For new cars we just simply wash and wax as needed.
The website has some excellent videos on how to wash a car, wax it and maintain the appearance.