I missed that GT-R LMP NISMO photo because the mobile site is failing to show page 5. How come leaked photos are always on a crap camera or uploaded in rubbish quality. It's 2015 people!
Despite the blurred photo and the fence blocking some of the car, it looks front-engined. The base of the windscreen is significantly further back than it's rivals which are virtually in-line with the front wheel.
Hopefully Nissan keep a predominantly red livery so as to differentiate the car further from the white of Porsche and Audi.
I don't remember any rumour about COTA and GT doing it's rounds. It is a circuit I would love to see though in GT7.