The Internets exploded yesterday following a photo tweeted by Tesla Motors CEO Elon Musk, with the caption, "About time to unveil the D and something else".

Feverish speculation over what it meant took up terabytes of server space.

Then, yesterday afternoon, a photo surfaced that purports to show a Tesla Model S "P85D".

DON'T MISS: Elon Musk Tweets Tesla To Unveil 'D' On Oct 9th: Our Guesses

Hmmmmmmmm.

The photo in question was posted to the Tesla Motor Club by forum member Adelman, in a thread discussing Musk's mysterious tweet.

It's a remarkably high-resolution image of the rear of a Tesla Model S, plugged in to charge, at an unnamed airport. The car has no license plate.

[UPDATE: Our reader Kees Versijde identifies the location as Inyokern Airport, about 150 miles northeast of Los Angeles. He notes that it's a popular site for auto companies to film upcoming models: It rarely rains there, the light is good, and there are very few people around likely to take spy shots. Of course, as the photo shows, only one is needed.]

Whether the photo is happenstance or a convenient "leak" remains unknown, but the net effect was to stoke the flames of discussion further.

Forty-two pages of forum discussion seem to have settled down to a consensus that "D" will be the designation for "Dual" motors--which is to say the all-wheel-drive option long expected as a new Model S option.

Such a car would be a spinoff from Tesla's AWD work on the upcoming Model X crossover utility vehicle, which will be offered only with all-wheel drive.

A number of commenters--among them Green Car Reports' own Chris O--suggested that perhaps the AWD model might be called "DD," for Dual Drive.

ALSO SEE: As Predicted, Tesla To Launch All-Wheel-Drive Model S For 2014? (Aug 2013)

Which would, as Chris suggests, explain why Musk didn't particularly want to tweet that it was time to unveil the DDs.

Ahem.

We'll find out late next Thursday, October 9, the date of Tesla's scheduled press and owner event.

[hat tip: SD_Steve]

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