I've used the Griot's clay with the Fast Shine for lubrication with no problems. However, if the paint really needs work (like my 328 right now) then zymol's HD Cleanse is a better product. The clay is great for routine prep. I've clay barred a few times, mostly using Meguiars claybar. This time I thought I'd try the stuff from Gratiots. What a sticky mess. It leaves clay residue on the paint and it makes a sticky mess on your hands. The Meguiars claybar outperformed by miles. It took alot of extra buffing to clean the clay residue off from the paint. But When I finally got the glaze and carnuba down, well the 'beast looks showroom. Its a shame I have to drive it and get it dirty.