My sister will be selling her 95 white Caviler soon, and so I will probably help her prep it. The car is not oxidized from what I can see, but it doesn't bead any water. There are a bunch of water stains, etc. that will need to be taken out so I was going to go with SSR3. However, before I use SSR3, do I need to clay the car first? Just thinking back to the old days when I used rubbing compound to smooth the paint. Wondering if it's a waste of time to clay as SSR3 would clean up the paint anyways.