A mule for a possible Mazda RX-9 has been spied outside the Nurburgring in Germany.

At first glance, the mule appears to be a standard RX-8, but closer inspection reveals the vehicle has an assortment of temporary pipes hiding behind the front grille.

There's also extra bracing around the front windscreen, as well as telemetry gear and other measurement equipment throughout the cabin.

Given the nearly stock body, this mule doesn't reveal much about how a possible RX-9 will look. It does seem to indicate the RX-9, or whatever is being developed here, will ride on a front-engine, rear-wheel drive platform.

This mule could be a precursor to a production vehicle, or it could be an engineering special to enable on-going development of rotary-based technologies.

If Mazda is working towards a production rotary engine-powered car in the near future, it's styling will likely be influenced by the 2015 RX-Vision concept and the 2017 Vision Coupe concept.

At the Los Angeles motor show, Masahiro Moro, president and CEO of Mazda's North America operations, confirmed to CarAdvice the company is still working on rotary engine development with a team of "dedicated engineers", but there's no product "on the official roadmap".

Earlier this year, Autoblog discovered a US patent filing for a hybrid drivetrain featuring an electric motor across the rear axle, and a rotary engine up front.

Such a layout was used underneath the Mazda 2 RE Range Extender prototype, and could be used in a future rotary-powered vehicle.