This year marks the 25th year of Mazda's evergreen MX-5 sports car. It's been a huge success story for the Japanese automaker--over 900,000 units have been produced over the past 25 years, across three generations of car--a much longer shelf life than most vehicles in the industry.

The car's 26th year could be the advent of something very different though, at least in terms of styling. According to Drive, one insider who has seen the fourth-generation car says it's a radical departure from the current vehicle. The new car looks "nothing like any of its predecessors," according to the source, who adds that current internet renders of the next-gen car are "vastly wrong".

In styling terms, existing MX-5s are more evolutionary than they are revolutionary, taking several cues from that first 1989 MX-5 Miata. While recent facelifts have given the car a less rounded look, several details remain similar to those original models. That won't be the case with the new car, which is expected to feature a new take on Mazda's current 'Kodo' design language. The large grill found on the Mazda 3, 6 and CX-5 won't be making an appearance, and the new car has "less prominent wheel arches" than the outgoing model. At the same time, it still has a "noticeable flow" to define the wheels.

At the rear, the new MX-5 will tout a rear diffuser under the bumper. Prominent rollover hoops sit behind each seat while the dashboard now gets a leather-look finish, taking it a step upmarket from the current car, the source reveals. There'll be retro touches too--body-color panels apparently feature on the interior door skins--similar to the use of body-color surfaces inside the current breed of retro small cars. A folding fabric roof, rather than a metal folding roof, is said to be standard.

Engine choices are expected to include 1.5-liter and 2.0-liter gasoline units, using Mazda's Skyactiv technology. The latter could develop up to 180 horsepower and enable a 0-62 mph time of around 6.5 seconds. Mazda is still aiming for a light curb weight too--current estimates put the car at around 2,180 pounds.

A debut for the fourth-generation 'ND' model is expected late this year or early next. In the meantime, click here for spy shots of a test mule.

Engine choices are expected to include 1.5-liter and 2.0-liter gasoline units, using Mazda's Skyactiv technology. The latter could develop up to 180 horsepower and enable a 0-62 mph time of around 6.5 seconds. Mazda is still aiming for a light curb weight too--current estimates put the car at around 2,180 pounds.