In October 2001 the W12 concept broke the 24hr endurance record.
300km/h average on a non-race prepped car is pretty good.
Then it was shown at Tokyo and called the Nardo.
The purpose was to showcase the new W12 engine, not the car. It was 2 fingers up to the established sports car makers though.
It was going into production - about a 100 they said. Then Bernd Pischetsrieder took over the helm - he cancelled it and resurrected it with a month - but nothing came of it. Then VW ran out of silly money, the Phaeton bled it dry and profits collapsed as the market became more competitive and VW suffered mas-market quality issues.
I would bet a serious amount of money that it will never get built - especially at a time when VW is trying to create more separation between brands, not confuse customers.