Well you see, if it's a 'recording', it's definately real. So...we can't really rate how 'real' it is, because it came directly from an actual M3 GTR on a race track (which EA had shown us in the past in an engine sounds video.
I just watched the video, and I must say it is deadly accurate compared to the game (or is it the other way around? ;p). Except one thing, the engine seems to be more high pitched in the video, so it makes the game M3 GTR seem like it's not reving high enough.
I would say it's hard to compare. I remember there is a pic showing how EA captured a car sound way back before the release of MW, cars were placed on a dyno, microphone was placed behind the car and not in the car. So definitely the sound is different from the one in the video which was recorded inside the car. Since BMW GTR is a track car with all the noise "insulators" being striped away to reduce weight, you would be hearing higher pitch sound directly from the engine and gear itself when sitting inside the car.
The Most Wanted/Carbon version sounds reasonably realistic. The real thing seems to sound a lot more whiney when it gets up there in RPM. The in-game gives off a bit of whine but its not all that audible.
I can't get over the sound and speed in the video, and the gear ratios are almost nailed on the head. Though its obvious that Carbon/MW M3 isn't exactly modified like this one is.
Seems like this website is a ghost town. No longer worth a visit or anyone's time.
You have to understand that not all sounds that are captured can be transformed directly into the game. some recordings need to be edited abit to make them work in the game. it could be that the higher pitch creates a unpleasant noise when playing etc.
EA placed more then 1 mic. they placed several mics in and around the car.
im pretty sure that i prefer the real life sounding m3 gtr. the ingame sounds are a little too dull imho coz i find it hard to know when the shift points are coming coz it sounds almost all the same, especially when its on the limiter - just sounds like it ran out of breath rather than it needing an up change in gear. in the video the sound of the m3 becomes more noticablly higher pitched when the revs were closing in on the limiter, this doesnt really happen in the game =/