A reader with sharp eyes and quicker reflexes sent us a pic of a Tesla Model S they had spotted on the streets of San Francisco sporting a trailer hitch receiver and a pair of portals of some type around back, which had us scratching our heads.

Tesla Model X with falcon doors slightly liftedThe Roadster, of course, doesn't come with a towing option (though the company's CTO JB Straubel does have a hitch on his) and the Model S wasn't slated to offer the option as far as we knew. So, we contacted the California automaker to ask what's up.

In a brief response, a spokesperson said "Tesla's engineering vehicles are constantly undergoing internal testing in a wide variety of circumstances to fine tune and validate performance, safety and durability" and confirmed that there will be no factory towing option. Of course, the Nissan Leaf didn't offer that function either but the aftermarket has stepped in with a solution.

So, if you want an all-electric that will pull your boat over to the bay, what are your options? A Leaf might not have the wherewithal for that sort of heavy-duty application, but there is something coming that will. The Tesla Model X (inset). According to the same spokesperson, "Model X will have towing capability exceeding most SUVs in its class. With all-wheel drive, incredible torque and sophisticated traction control, it will be an excellent towing machine."

Awesome. Thanks to Eric for the tip!