The Cadillac Ciel concept car gives us some clues about the upcoming big Cadillac's styling. Photo credit: General Motors Co.

It's no secret that General Motors (GM -0.17%) is working on a major overhaul of its old luxury brand, Cadillac. And it's no secret why: A successful luxury-car brand can be a huge source of profits, and profits are a big priority for GM CEO Dan Akerson.

Akerson just confirmed that the next new Cadillac will be a full-sized sedan, a true American rival to the Mercedes-Benz S-Class. In this video, Fool.com contributor John Rosevear gives you the full scoop on the upcoming big Caddy, and a surprise: We may get a look at this big new car very soon.