What happens if I wait too long to level a ceramic coating?

If the coating starts to cure before it is leveled, it becomes difficult to wipe, leaves streaks and smears, and can turn into high spots. Heat, low humidity, airflow and direct sunlight shorten the working window. If wiping suddenly becomes hard, stop and apply a little fresh coating to the area to soften it, then level immediately. Working in smaller sections and checking each one as you go prevents most of these problems.