This is one of those cars that has been spotted a few times over the years, but I don't believe we've ever been able to confirm the chassis number. As you must know by now, this is always very frustrating to me. Here's a new image of it I found recently that obviously dates back several years, again being displayed along with other noteworthy McLaren F1s.
The fact that this F1 was used by Jeremy Clarkson in one video and that it was seen in some of McLaren's promotional displays makes me think there was some tie in with the factory for this car.
The most logical possibility would have been Ron Dennis' chassis #003 given that visually this car seems to match that one quite closely. Most of the confirmed shots of #003 show it wearing the 'K4 MCL' plate however, but even more importantly, and what I believe clearly excludes #003 is that this F1 wears the later style side mirrors from the sourced from VW.
Chassis #011 and #024 were both painted "Carbon" originally so I guess it is safe to assume it would have to be one of them. The earliest images of #011 show a red stripe on the ventline of the door and a plate that read 'M351 HPM' so possibly that should be excluded as well. Beyond those comments I don't have any solid details to go on. I guess I am hoping an insider will see this and have some recollection. Otherwise, we'll just enjoy the picture I guess.
>8^)
ER