I was claying my 01 white BMW today. I continually reshaped the clay as per the directions. On some of the harder spots, I would go across then up and down to lift the embedded dirt. Almost like a cross. I lubed it heavily while doing this. I only used the cross motion on the harder spots that wouldn't lift just going across. Now I can see minor scuffs in the clear coat. Uggghhh. What did I do wrong. I checked the clay regularly to make sure it did't have any pieces of dirt in it? What do I do about the scuffs now? They are minor and you can't feel them with your fingernail. Will the Z5 cover that up? No more clay for me.