Clay can be a great tool, if required. Clay removes contaminants on the surface. If your paint has contaminants firmly bonded, the proper use of clay is a timesaver. However, if the paint is clean, clay is not necessary. I use clay to clean up my daily driver, but on my other cars it isn't necessary or desireable. Wash the car and feel the surface. If it is smooth, a light polish with a swirl remover and some wax should be all you need. If you feel contaminants, use clay with lots of the correct lubricant - quick detailer, final inspection, etc. Follow with a light polish with swirl remover and wax.
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex