The small, swoopy Mercedes CLA-Class debuted a refresh for the 2024 model year, but the next-generation model is already undergoing testing. We've had a couple of curious prototype sightings featuring cars covered nose-to-tail in camouflage, though there were questions on whether they might be all-electric EQA sedans. Now, we know that internal combustion will live on for the next-gen model.

We have our spy photographers in Spain to thank for that. Caught testing at higher elevations, the heavily camouflaged Mercedes seen here isn't covered quite well enough. Thanks to a combination of good positioning and bright sunlight, there are two features that identify this test vehicle as combustion-powered. First is the lack of a visible charging door on the right side, a feature we clearly saw on a prototype during winter testing in the north. Instead, we see a door on the left side – neatly matching the position of the fuel door on the 2024 CLA.

Gallery: Mercedes-Benz CLA-Class Spy Photos

The second item isn't a literal smoking gun, but it is smoking. Zooming in on the bottom of the rear fascia, the photographer captures a single exhaust pipe hiding in plain sight. It's mounted well behind the fascia, exiting to the right of the number plate. Moreover, we don't see any evidence of this being a plug-in hybrid model, so we're likely dealing with the familiar turbocharged 2.0-litre four-cylinder incorporating a 48-volt mild hybrid system.

Those are the primary takeaways from this batch of spy photos. The exterior remains heavily covered, with all kinds of panels and deceptive lumps covering key areas at the front and back. It's all wrapped in white/black camouflage, and placeholder taillights are easily visible at the back. Meanwhile, the headlights are surprisingly detailed, giving us a preview of new oval-themed eyes flanking a grille that's likely lower than what you expect. Note more false ridges on the bonnet that make the front look taller than it really is.

The next CLA rides on the Mercedes Modular Architecture (MMA) platform. It's designed to accommodate all the powertrains – battery electric, plug-in hybrid, and combustion power. We've now seen at least two versions if not all three, but it will likely be quite some time before all is revealed. The facelifted 2024 CLA is still brand new, so expect a next-gen debut well into next year or even longer.