I was curious when I read your forum post whether there was a quick solution to what you are trying to do. As per Cormac’s email, we do not provide a specific blurring mask tool or a motion tracking tool that you could apply to blur the number plate, as per the TV shows etc.
However, if it was a relatively short clip and you wanted to simply prevent some element from being shown, you could implement the fix that I have applied in the video below. Don’t get me wrong - it is pretty quick and dirty, but could be a quick solution if you needed:
