Do you ever stop and wonder how a Volkswagen version of the Porsche Panamera would look? At the 1999 Frankfurt Motor Show, the VW Concept D was a taste of things to come as far as the Phaeton was concerned and took the shape of a swoopy large sedan (technically, it was a five-door liftback) with all the luxury Wolfsburg had to offer. It came with a mighty V10 turbodiesel engine, air suspension with adaptive damping, and lots of cool toys. It went on to become the D1 in 2001, which was nearly the same as the production-ready Phaeton.
You can read all about the 1999 VW Concept D here.