Unfortunately, I don't have any documentation, but there are so many things that scream AMG (besides the badge). The lowered suspension, the wheels, the body kit, the wing... I know that all of that could have been put on later by some random person, but I doubt anyone would go through that kind of effort and then treat the car like crap. And then there's the transmission, which is a 5-speed manual. From what I've heard, and from my own experience, manual transmission Mercedes are almost non-existent.
I will admit there are a few things that make me wonder. For example, the grill is chrome, instead of black like it should be. However, I wouldn't be surprised if the original was lost or damaged at some point and replaced with one from another car. Also, the steering wheel is stock Mercedes, and I was under the impression that AMG put their own in most or all of the cars they modified.
That's part of the reason I joined this forum. I want to know if it is in fact an AMG, and see if I can get some help or recommendations on fixing or replacing damaged/missing parts.
And I'll be sure to get some pictures up soon.