After taking another look at the recent spy shots, I’m now convinced it must be the 2012 Lexus GS under all that camouflage — here’s a better comparison shot with the LF-Gh concept (plus a little photoshopped perspective in the spy shot):
Most obviously, the side skirt is identical, along with the rear window shape, the wheelbase, and overall profile — in fact, looks like the LF-Gh’s entire side profile has been carried over into the production model. As well, taking the wheel gap into account, we may be looking at the AWD variant.
Any differences are hard to spot with all the camo, though it does look like there’s a full bumper across the front fascia rather than the open grille design seen with the LF-Gh.
Finally, let’s look at the rear photo again with a better comparison shot:
From this shot, it looks like the car’s greenhouse has been made taller and the rear lights have been changed, but it appears the concept’s integrated exhausts have made it to production.
Of course, this is all speculation based on some grainy photos of a car completely covered in camouflage — any & all impressions should be taken with a grain of salt.
(Special thanks to Club Lexus member Mr. Burns & his inspired line drawing.)