- Immediately after arriving at a car show to safely remove whatever got onto the car during the drive. DS will come afterwards when the paint is clean and dirt-free.
- Wiping down door/trunk/hood jambs before washing the car, so when water flows through it isn't bringing that dirty water out onto the paint.
- Drying agent. Many people use DS here but I prefer WW as it helps get rid of stubborn spots that did not come off with the regular wash.
- Pre-wax cleaner. After polishing a panel I will use WW to wipe down the panel before applying wax or sealant so there is no polish residue left behind. Other people will use IPA but I feel this is safer (and more pleasantly-smelling). I also use is to clean up wheels and exhaust tips before putting QS on them.
I've had mixed results using WW as a wash bucket additive and I can't pinpoint the cause. It adds lubricity but sometimes it will mute the suds created by the shampoo.