I think there's only one Holy Grail (as in 'The' Holy Grail), but strangely, we've seen a few of them lately. I'd like to make a claim for the title.
Does having a Factory 5-speed make it a holy grail? In which case there are a few hundred of those.
There was also that other holy grail recently with black valve cover. But we know there were a few of those.
I think my car is the holy grail. It has a Factory block heater. I've never seen another one with that.