I'm getting tired of reading this.
The X1 was the original name given to the car.
For whatever reason, the name was CHANGED BY PD to the X2010.
All of this talk about "X means Experimental and 1 means top of the class" is all complete nonsense. The original name of the car simply was X1, and the reason that there was the added 2010/11" was more than likely to avoid legal conflict with the BMW X1.
Either way, it doesn't matter. X1 or X2010, people in GT5 will know what you're talking about.
For us in the USA, take this example. The president is Barack Obama. But do you refer to him every time as that? Or do you simply just call him "Obama" or "The President"?
The true and formal and correct name is the X2010/11, but even if you just say X1, it doesn't matter too much in the world of GT5.
Now that this has been clarified, bickered over, and discusses far more than necessary, can we please end this talk of the name?
In the end, it doesn't matter. X1 or X2010/11, in the end it's still the fast car made out of ridiculous numbers that's basically unbeatable, and the addition/exclusion of 3 letters should really not cause this much uprest.
Most of you are presumably mature adults, so I'd desperately hope that you all can realize how pointless the arguing over this name is and just get on with what the topic of this thread truly is about.