The way to prevent scratches is to use a safe wash/dry process and not touching the paint any more than needed. A wax will not prevent the scratches.
What is your wash and dry procedures?
You need to wash using the two bucket method where one bucket has the soap and a second bucket to rinse the mitt to keep the soap clean and risk re-introducing dirt back on to the paint. You should not be pressing down hard as you wash. You need to use a good quality wash mitt like Mothers mitt and then dry using microfiber towels. As always, work clean using clean mitts and clean towels.
Mothers Detail Guide gives some pointers on how to wash and the videos on tips: