I never used the ceramic coating just the sound deadener , but I used the $75 dollar bucket ( 2 gallons?) and it covered the floor ( 3 coats ) .
I had the dash removed because I was rebuilding the truck from scratch, I did however keep the foam insulation between the dash and firewall .
With a wet rag the lizard skin wipes off easily if you happen to get overspray on something , but I would mask everything you don't want sprayed .