I play on a 21:9 Curved 34" screen from Dell. It is awesome. And i prefer it above triple screen.
It has a lot of pixels (3440x1440) to render though, so to power it good, it needs serious Graphics horsepower.
Shadowplay recording does only partially support it. I record at a lower res (2560x1080) at 60fps. It only does 30fps on full res. And i still need a better video editor than the one i use now.
For racing games it is very good. Just a bit better view on turning points. And the sense of speed is a bit better than on a traditional 16:9. But i tone down motion blur wherever i can.
Back OT: The car is an Audi R18TDI LMP1. No E-tron.