While at the ring I spoke to a couple of new GT3 and RS owners had had McLaren's before. They said they switched back to Porsche as the consumables on McLaren were just too high.. namely windshields that wouldnt last a track season, paint quality being so so and engines being fragile however what got them out was the fact McLaren doesn't release much repair info for the cars to 3rd parties.. thus requiring you to visit the local approved service center which if you track the car follows some absurd maintence programs... Yea one said "I can afford it but spending that sorta of money is simply foolish for x amount of track hours vs cost" and if you don't follow it and blow up an engine ur SOL.
So while The Senna was made for track purposes and some will come out to play I bet most will stay locked up