Spy Photos: Mystery car following 350Z mule?

Several photos have popped up in the last week of a Nissan 350Z –based mule that has been circulating on public roads. The prototype is clearly based on the existing car but with a shortened greenhouse. World Car Fans has a bunch more photos of this car today, but in the first photo the mule is followed by a second mystery car that may in fact be more interesting. Featuring a single blade wiper and what may be rear quarter air scoops, this one may not have turned up before. If anyone has any clues as to the identity of this other car, please chime in the comments or send us a tip.
[Source: WorldCarFans]