I bought the DG Enviroshied kit and am using it on my new F150. Here are a couple questions.

1. What is the affect of Enviroshield applied on black plastic trim. Does it help or hurt trim? Should trim be masked off? I really want to avoid any discoloration.
2. Does a second coat add to protection or simply remove the first coat. How long to wait between coats?
3. My first coat consumed about 1 oz. I'm not really sure if I was too stingy. Does 1 oz sound about right for a full size pickup?
4. What happens in a year or two when Enviroshield is no longer effective. What's the prep work to repeat the process. Will Squeaky Clean remove old residual Enviroshield?