This is the first time I have seen this particular 'arm rest' in a picture of a McLaren. It is definitely not something that was issued by Ford for Mustangs. Is this a McLaren item or is it something that was added to this car. I love the look of it, but I don't think it is a standard McLaren item ?
My suspicion is that it was an aftermarket item, simply because this is the first time I have seen such an odd arm rest used in a McLaren ( based on all the pictures I have viewed of McLaren interiors ).
The other reason I suspect this 'youngster' (with 20k) was tinkered with is that the steering wheel is a standard issue Ford with the blue oval in the center - instead of the imprinted (stamped) McLaren.