Ok, so I'm clearly not alone! Thank you for all the info. I've asked the dealership to push back on the warranty company and to check with McLaren NA. I'll report back - hopefully the warranty company back down from their BS stance or McLaren NA step in.
FWIW here is a picture of the crack. It's quite hard to see as the crack is hard against the door and you have to sort of put your head between the door and body of the car and then look "up". But it's definitely there. As for how serious it is, I'm not sure but engineers don't put four bolts if they only need three.
There was a question of wear and tear from @ImHuntingWabbits
. The crack on my car is on the passenger side which gets far less use than the driver. I have heard that the doors are very heavy (as they form a piece of the side impact safety system) and it takes two people to safely lower them down when undoing the bolts. So that hinge does have its work cut out. And, again, I definitely would not want the hinge to suddenly fail either while driving or getting in or out of the car (that could cause serious injury).
There was also a point about alignment @VGJ
, well that passenger door was misaligned and it caused the door to rub against the jam which then wore through the wrap and paint down to the metal on both door and jam. That I see as annoying but cosmetic and have learned to live with.
And finally @Zarakoff
, yes, the e
xtended warranty (which cost US$5200 for 12 months - I looked it up on the contract of sale) does seem to have questionable value. I won't be getting it again.