Mark your calendars! On October 9, Tesla is going to announce…something. Elon Musk has issued one of his famously cryptic tweets, to wit: 

About time to unveil the D and something else pic.twitter.com/qp23yi59i6

— Elon Musk (@elonmusk) October 2, 2014

The mysterious missive is accompanied by a picture of what is undoubtedly a Model S peeking out from under a garage door emblazoned with a big stylish letter D.

So, what is it going to be? It probably isn’t going to be a brand-new Model D, but several EV-watchers have speculated that it might be an all-wheel-drive version of Model S. Tesla has already developed dual-motor AWD technology for Model X, and it has hinted in the past that an AWD Model S might be a cool thing, so…

And how about that “something else?” A free trip to Mars with every Model 3 pre-order? Perhaps, but most of the Teslarati are talking about a new feature for the Roadster. At the most recent shareholder’s conference, Musk said, “We’re going to do something cool with the roadster later this year.”

Well, later this year is upon us, so this may just be it. A second-gen Roadster seems unlikely to be announced before Model X is on the road, but some sort of a retrofitted upgrade is a possibility. In July, Musk said the Roadster would get “a new-generation battery pack [that] should have a range of about 400 miles.” Is that already considered old news, or could it be the “something else?” We’ll be getting up way before dawn on the 9th and racing downstairs to our computers to find out.

UPDATE: The day after the tweet, a mysterious photo appeared on TeslaMotorsClub.com showing a a Model S P85D – definitely a new version of the S, and quite possibly a Dual-motor AWD version.

Source: Elon Musk, Jalopnik, Auto Express