The Lamborghini Aventador J isn't a concept but it is a special edition automobile. While Lamborghini doesn't list much as far as specs, I know if I see one of these pull up, i'm already assuming it's got some real power behind it.
Straight from the Lamborghini site, "It combines the overwhelming performance of the Lamborghini Aventador with the most intense experience of power and dynamics imaginable in an automobile."
