Not sure where I stand right now on the subject of the X1, before GT5 was released I defended its inclusion as an 'intellectual exercise' for a racecar without abiding any regulations or restrictions apart from the laws of physics, an age old question speculated upon by many petrolheads how that would appear and drive like, finally an example how it could be to experience in a driving sim.
After driving it, and until now failing to even achieve bronze in the Vettel challenge although I have only given it a few tries (which hasn't affected my judgement on the car itself by the way, and I'm planning to give that challenge some proper attention soon), it just seems a bit too much for me.
Adrian Newey himself recently admitted, smilingly, that a real life version would be so stressing to drive for a driver, he or she could only last for a few laps.
People often use the example of fighter pilots suffering similar G-forces, etc. although they have the freedom of an almost empty sky to manouvre around instead of the narrow confines of a track.
So although I do believe this car could be build and perform in a similar fashion like the one in the game (although it would have to be thoroughly re-designed and tested I guess) it seems it could only be able to race when the driver sits in the pit area behind a screen holding a steering wheel or controller....
Perhaps it would've been better (both for real life accuracy and for the game) if both Kaz and Newey took the ability of being able to drive it more than a few laps in real life into the equation.
That's what would've been done when the car was build for real life instead of only for a videogame.
So yep, it's realistic no doubt, just not meant to be driven in reality.