2015 Mazda MX-5 teaser photo posted on Facebook

The event invite page, titled "2016 MX-5 Miata Reveal", was setup by Mazda USA's official Facebook profile. The event's banner image is of a two-seat roadster under a shroud of sheeting (above). If this is indeed the next generation MX-5, it looks like it will feature a version of the third generation's prominent wheel arches and long hood.

Aside from the photo, the event page doesn't reveal any new details about the fourth-generation MX-5. It does, however, state that the unveiling event at a "secret location" on September 3 (by then September 4 in Australia) will be streamed live on the internet and will be followed by a "live concert with special guests".

The latest MX-5 revelation on Facebook follows on from photos of a camouflaged fourth-gen car undergoing testing on public roads in Japan. Those images were uploaded to the internet through picture sharing website Imgur.

Previous public sightings of the new MX-5 involved the new car's chassis being mated with highly modified versions of the third-gen car's body work.

With the reveal in just under a month's time, Mazda has done a good job of keeping details about its halo car under wraps. We do know, though, that the new MX-5 will be shorter than the current model and will shed up to 100kg, meaning that it will tip the scales at around the one-tonne mark.

An earlier teaser video from Mazda hinted that new car will feature a turbocharged engine, at least in some variants. The new MX-5 will also be the first to have a sibling, with Mazda building a uniquely styled Fiat version alongside its own roadster.

When the new MX-5 is launched in Australia around the middle of 2015, it will likely start from below $40,000.