Regarding using a clay bar for prepping the surface, this is a personal preference, and it's up to the customer on how comfortable they are in their skill level for clay barring. Improper clay bar use can induce problems that The Last Coat would not be able to solve. Anytime you clay bar you would follow up the same day with protection such as The Last Coat within in hours after completing. Ideally, you wash the vehicle rinse it off then start the clay barring process using a clay lube to ensure you are not dragging clay across the dry paint. Ideally try to use a clay lube that contains little to no waxes for best results with TLC. You can use The Last Soap diluted as your clay lubricant. Then once you have clay barred all the paint, you rinse again and dry or wipe clean with a few microfibers. Finally after all that you would then apply The Last Coat. Proper clay barring as the initial prep step will often give you the very best results out of TLC. Now, regarding using The Last Coat as a base lubricant, DO NOT use it as a clay lube! The Last Coat would be used as a follow-up step for protection after claying, or any paint correction work that is done mechanically or by hand.