October 21, 2026
Unique BMW 3 Series With Sliding Glass Roof Stars In New Video

BMW has built its fair share of unusual prototypes over the decades, but this one-off Karmann creation is one of the more intriguing experiments based on the E36 3 Series. The K2 combines a pillarless coupe with a pickup truck and a convertible, all wrapped into one decidedly unconventional package.

As you may recall, we talked about this rare machine at last year’s Retro Classics show in Stuttgart, Germany. Now, a new video from retrogarageofficial on Instagram offers another chance to appreciate this unusual take on the third-generation 3 Series.

Suffice it to say, the K2 isn’t your typical BMW. Rather than simply chopping off the rear end of an E36 and adding a cargo bed, Karmann created an elaborate roof mechanism that transforms the car in several stages. The rear window slides beneath the metal roof, revealing a small bed with a folding tailgate.

Photo:
Gudrun Muschalla / BMW Classic

The Most Versatile 3 Series E36?

That’s only part of the trick. The entire roof assembly, including the glass panel, slides back to cover the bed, turning the K2 into an open-top car with dramatic flying buttresses. The small rear quarter windows are retractable, too, helping maximize the open-air experience.

In other words, this unusual BMW can switch between coupe, pickup, and convertible configurations. It’s an ambitious solution to a question nobody was necessarily asking, but that’s what makes the K2 so fascinating.

The design also borrows a few sporty details from the BMW parts bin. M3-style wheels and mirrors give the car a more aggressive appearance, while a third brake light sits at the edge of the movable roof panel. Even so, the K2 looks nothing like a conventional E36, especially when viewed from the side with its roof and rear glass retracted.

Some uncertainty remains about the car’s origins. Karmann’s now-defunct website described the K2 as being based on the E36 Compact, although we lean toward the coupe as the starting point. BMW itself doesn’t appear to have detailed information about this unique project in its archives.

Series Production Didn’t Make Much Sense

Whatever its exact underpinnings, the K2 was never destined to become a regular production model. Its complicated roof mechanism alone would likely have made it expensive to manufacture and maintain, and the combination of three body styles would have made it a niche proposition.

Still, that’s part of the appeal. BMW has occasionally explored unconventional body styles, including factory-built pickup prototypes, but the Karmann K2 takes versatility to another level. It effectively offers three cars in one, without resorting to a modern crossover’s ability to pretend it’s everything to everyone.

Photo:
Gudrun Muschalla / BMW Classic

It also reminds us that the automotive industry once had plenty of room for strange experiments that never made it beyond the prototype stage. The Karmann K2 might not have been a commercial proposition. Still, decades later, it remains an excellent example of what happens when engineers and designers decide that a conventional coupe simply isn’t enough.

Interestingly, this isn’t the only unusual E36 to surface in a recent video. We recently covered another one-off: a five-door 316i E36/5 Compact that BMW Classic also pulled from its vault, revealing a hatchback version that never made it to production. That car and the Karmann K2 show two very different ways to rethink the E36 formula, proving that BMW’s third-generation 3 Series had plenty of untapped potential beyond the familiar sedan, coupe, convertible, wagon, and three-door hatchback.

Video: retrogarageofficial / Instagram

First published by https://www.bmwblog.com