Quick and dirty comparison between the VJM02 and the McLaren. Rotation on the photos is a couple of degrees out, so it's difficult to judge exactly, but it looks like the cars are identical in length and all but identical in wheelbase.
Front suspension is pretty close as well, with the unusually (compared to the other cars) rearward mounting of the top wishbone.
Airbox snorkel and seat look like they're in identical positions. As far as I can tell the sidepods start in the same position as well, although they're more undercut on the FI.
Definitely looks like McLaren have been at least sharing some data with them. Very very interesting.