Though, I’m not sure where the “Limited” part comes in.
You can already spec an RS3 in Nardo Gray, and you can spec it with 174mph top speed by opting for the Dynamic Plus Package.
I suppose this one might permit the higher top speed without opting for Dynamic Plus...which sounds unwise: If I’m going to try to top out at 174mph I’d definitely prefer to have the ceramic brakes to slow me back down to sane speeds!
Edit: Never mind. I looked at the configurator and it appears that the Dynamic Plus package is no longer available...so this is the only way to get that (pointless) higher top speed.