In the Nvidia video they are using OLED screens from another HMD. It looks like it has a bunch of microlenses on top of it, maybe 200 or so. So it seems like resolution would be a big issue since small form factor OLEDs only go up to 2560 x 1440 in current devices available to consumers.
[0]http://www.chevrolet.com/2016-volt-electric-car.html