Lamborghini teases engine sound, but of Sesto Elemento or Cabrera?

Lamborghini has launched a website for something it calls the Hexagon Project. The mysterious page asks that you submit your email address, and then it gives you a taste of glorious V10 engine noise, with the message: "Listen to your instinct. Discover the roar of a new creature from Lamborghini. That will be just the beginning.".
But where is that wonderful noise going to come from? Since we don't see Lambo launching a front-engined, front-drive minivan in the near future, we're guessing it'll be found in the back of some low-slung, edgy super car.

In our minds, that leaves two candidates.

Autoblog , Lamborghini teases engine sound, but of Sesto Elemento or Cabrera?, Lamborghini teases engine sound, but of Sesto Elemento or Cabrera?