The C6’s Rear Window Looks Backward, but Its Shape Had a Practical Purpose

The original Citroën C6 had a concave rear window that curved inward across the back of the cabin. Besides giving the saloon its distinctive appearance, the shape allowed the boot lid to extend toward the glass, helping access to the luggage compartment. 

The C6 is a car worth walking around slowly. From the side, its long roofline flows toward the rear with the confidence of a large, expensive saloon. Move behind it, though, and the glass does something unexpected. Instead of bulging outward, it seems to retreat into the cabin.

It can take a second look to understand what is happening. Reflections bend across the surface, the middle sits farther forward, and the boot appears to reach around it.

Citroën could easily have used a more familiar shape. Instead, the rear window became one of the details that made the C6 recognizable even without a badge. The launch material presented it as a reference to the company’s earlier large cars, while also emphasizing rearward visibility. 

There was a useful consequence beneath all that glass. The inward curve let the boot extend farther forward toward the window’s edge. Citroën’s original press kit explicitly linked that arrangement to easier access when loading luggage. 

It did not turn the C6 into a hatchback. The glass stayed in place when the boot opened, so anyone expecting an enormous liftback aperture would still find a conventional saloon underneath the unusual outline. The benefit was in how the opening fitted around the rear of the cabin.

That is an appealing detail because it gives the shape a second life after the initial surprise. At first, the window is something to notice in a photograph. Open the boot and there is another reason for it to be that way.

The rest of the body rewards the same attention. Frameless door glass helped give the large saloon a lighter, almost coupé-like appearance, while the long doors and generous glazed area kept the cabin visually open. These were deliberate parts of the design described at its 2005 unveiling. 

None of this requires the C6 to be defended as the most sensible possible car. Its appeal is more specific than that. Someone considered the ordinary business of opening a boot and managed to work an unusual piece of glass into the answer.

Stand behind one, slightly off to the side, and follow the reflections across that window. It remains a lovely thing to discover.