Tesla is known to be quite the innovator. Along with its Roadster and Model S, the next big thing to come from the EV automaker is the Model X crossover. We also know that an entry-level model, set to be called the Model III, is due in 2016. But we know that Tesla won't stop there. And now Tesla founder and its CEO himself, Elon Musk, is lightly hinting that something else could be in the works. In a recent interview, Musk stated that "People have gotten used to us showing all of our cards. We're not currently showing all of our cards.

Our capital expenditure and R&D numbers are better than they appear because there are things you don't know about." The question now is what is Musk referring to, specifically? Treehugger.com has a few guesses. First off, this could be a clue regarding the also rumored electric pickup Musk has previously mentioned he'd like to do one day. Another possibility is an even more affordable EV slotted below the Model III. Or, perhaps, Musk is hinting at even more rapid expansion of its upcoming Gigafactories. Whatever this secret project is, we're anxious to find out.