Mercedes->ke187' much-needed C-Class Convertible is inching closer to production as the Stuttgart-based company continues testing the cabriolet throughout Germany. Scheduled to break cover at the Frankfurt Motor Show->ke235 in September, the 2015 C-Class Convertible will be the first drop-top in the model's 21-year history.

Our spy photographers recently caught the cabriolet C-Class stretching its wheels on public roads for the third time since September 2013. Things haven't change much since May 2014, when the prototype was spotted testing with the same camouflage pattern covering its body, but a few new details suggest development is well underway.

Once it hits dealerships, the C-Class Convertible will join its sedan->ke142 and wagon siblings, while waiting for the AMG-prepped versions to arrive. And yes, at some point, the convertible will benefit from AMG->ke8 treatment as well, including the brand's newly developed, 4.0-liter, V-8 engine and the enormous amount of power that comes with it.

Click past the jump to read more about the 2015 Mercedes-Benz C-Class Convertible

Spy Shots

At first glance the C-Class prototype depicted in the photos above is identical to the one our paparazzi spotted back in May. Take a closer look though and you'll notice the cabriolet rides on a new set of alloys wheels. It might not seem like a big deal, but a new set of wheels suggests Mercedes engineers are testing various suspension settings on different type of wheel sizes and designs. When cars like the BMW 4 Series and Audi A5 are waiting right around the corner, you need to make sure the chassis is properly tuned before the production line fires up.

Other than that, this test vehicle has nothing new to share with us. Every inch of the body is covered in swirly camouflage, including the soft-top, the headlamps are mostly hidden behind duct tape, while the taillights have yet to grow into production units. However, the overall design is not much of a mystery, as the C-Class Convertible will borrow most of the styling cues seen on the sedan, save for the rear doors, the retractable soft-top and the trunk.

A similar transfer will occur in the engine compartment, with most gasoline and diesel mills to become available in the cabriolet. In the United States, the C-Class Convertible will go on sale with two powerplants under the hood. The 2.0-liter four-banger will deliver 235 horsepower at the bottom of the lineup, while the 3.0-liter V-6 will inject 329 ponies in the mid-range model. Both units will mate to seven-speed automatic transmissions.

Why It Matters

Being the first cabriolet in C-Class history, the 2015 Convertible is definitely a vehicle we should keep a close eye on. With the C-Class sedan having already been unveiled, we're pretty sure the convertible will turn a few heads once it hits the streets in production guise. With stiff competition coming from BMW and Audi, the convertible compact market is about to become an even more disputed playground. And that can't be bad, right?

Mercedes C-Class Convertible - rendering