Perhaps for normal joe cars, but right now some people with really expensive stuff can't get out of them because even dealers who sold them it new 6 months ago won't take them into stock or even bid on them and you can be sure a WBAC would not go close to it. To my thread about car prices the market is in free fall at the moment and with 349 McLarens for sale on Pistonheads, it's not surprising. Oversupply is great for the new buyer, but come resale then BOOM. At least on a 3 year PCP you can give it back, if you own it, you are roger'd with a big roger.
Great though for you mate if Mclaren is your next choice, at the current freefall the idea of 570S be out the window and you'll be dropping into a 720S.
Mclaren used is not appealing to so many because there are no specialist because of the silly rules Mclaren set unless things have changed now, so there decisions to not support used and aftermarket is really going to end up biting them so hard in the backside.
Next year, especially if you wait I can see you landing an insane deal, if we think things are looking good now and I can see Mclaren been hit insanely hard next year, especially if they also release another 4-5 new models as expected as well.
Not that I like them but MP4-12C's are swapping hands for 70k, reason been because they are pushing and selling so many, then the after support is truly lacking on used stuff and without warranty they will prove very expensive to run and the people I know who owned 12C's all had issues with them, bloody quick cars though.