On the basis of exotic I'd have to say 12 cylinders.
It will probably remain so as more manufacturers move to 8 & 10 cylinders for their top end cars.
Rarity of 1GZ helps, built in small numbers, (wonder when they will stop?)
Lets not forget the sound, to some, 12s (or 10s) would be awful, I can't wait! Mmmm, Pagani Zonda to name one tasty sounding car.
What about this, MA61 V12, 6,000rpm, possible? sure hope so.
It will sound like an MA61 doing 12,000 rpm, is that exotic or what?