Hello my friend
Unless you carefully clean out that duster EVERYTIME you use it,it may trap in sand,dirt and other nasty stuff that may cause you to Scratch or even leave those ugly swirlmarks
.Always use a microfiber towel with your choice of detail spray.The detail spray will help as a lubercation.
If the car does not need a WASH,it may just may need a quick rinse to remove the road grim,This is how you will know:
When you wipe the car down with your microfiber towel and if there is ANY heavy dirt,normanlly toward the bottom of the car and rear,then it could use a quick rinse,when rinsing use a slow flow of water and take off any nozzle you may have on the hose and let the flow act like a sheet of water,that does 2 things,First it gets the bulk of the dirt off and second it makes it easier to dry.
Dry the wet area and spray with detail spray,then you should be good to go.
Again congrats on your new baby.