I've read that some people use car wash detergent and water as a clay lubricant. So a couple of months ago when I clayed the car in preparation for a new application of Klasse, I gave it a try. I was very pleased with the results.
Here's what I did:
1. Wash the car thoroughly.
2. Rinse well, but do not dry.
3. Fill a spray bottle with a strong solution of car wash detergent and water (like 1:8).
4. Spray a panel with the solution and start claying.
5. Rinse the panel.
6. Repeat until all panels are complete.
7. A quick wash to assure all the clay residue is removed.
7. Final rinse.
This leaves you with a perfectly smooth, squeaky clean finish ready for polishing. The car wash solution is cheaper than QD and works better, IMHO. You only have to dry the car at the end and you don't have to worry about buffing off the QD. And for the purists, you can determine the real condition of the paint without the gloss enhancers left behind by the QD. I use DuraGloss Car Wash 901 which has very good lubricity.
Formerly, when I used QD as a clay lubricant, I had to wash the car again before polishing to assure that the Klasse AIO would bind to the surface. So this saves a step for me.