When I was putting on 2 coats of zaino, I couldn't get off some of the sap and some of the impurities of everyday driving. What is the best clay bar to use later on and I start the process over fresh?

 

I don't think there is any real differences with claybars. They just have to be soft. Claybar is used to clean everything off the car, so it's starting from the beginning as far as putting all the wax or Zaino back on. You might as well get the buffer out and work out any scratches while you're at the clearcoat.

It is worth it, after claying the finish will be incredibly smooth. Just remember to keep the clay lubricated and clean. Don't want to drag grit across the bare clearcoat.