A heavily camouflaged test mule that can only be a was just spotted outside Auburn Hill, Michigan. Spy photographer caught it in action and . Design details are all obscured under wraps, but the basic shape is true to the current Wrangler pictured here.

The spy shots show a four-door Wrangler wearing the wheels from Jeep’s most aggressive Rubicon trim. The red struts you can see in the rear-shot make it look like it has the hardcore stock suspension, making me think this is a Rubicon prototype.

The Wrangler Rubicon of course is the top-of-the-line off-road Jeep with locking differentials and a disconnecting swaybar as standard equipment. It also has the best stock transfer case which gives low range maximum bite for rock crawling.

Aggressive Goodyear tires like the ones you can see in those photos has been standard equipment on some current Wranglers (BF Goodrich is usually the other knobby option) so it doesn’t look like any big changes are being tested there yet.

That said, I wouldn’t be surprised if the BF Goodrich KO2, a relatively new versatile and practical off-road road tire, becomes the standard “upgrade” option in the next Wrangler. That tire’s been marketed hard and universally accepted by both desert and mud-driving wheelers as one of the best options for trucks that get used both on-road and off.

As for the prototype itself, it’s hard to tell anything about it other than the fact that it has a strikingly flat windshield and what looks like a long “chin” as the bumper protrudes significantly.

But those details might both be part of the camo; moving to a curved windshield was one of the biggest aerodynamic upgrades the current (JK) Wrangler got when the design was introduced in 2007. And it’s already been confirmed that the next Wrangler will lose like great-grandpa Willys.

Supposedly the next (JL) Wrangler will be a lot lighter and sleeker than the current car, which is why the fans have been leery of what the next rig in the line might look like.

Since the entire Jeep brand is basically built around the aesthetic and attitude of the Wrangler, I don’t think any fans have to worry that the next one will be dramatically different in ways they won’t expect.

It’s also been hypothesized (by me) that Jeep may continue to sell the current Wrangler as a “Wrangler Classic” for the first year that the new vehicle is introduced, most probably late 2017.

That gives us plenty more time to hunt for hints and start rumors, so stay tuned for Wrangler news as it breaks!