Since it was co-developed with the BMW Z4 roadster, Toyota only sells a coupe version of the new GR Supra. But that hasn't stopped the Japanese automaker from building a one-off open-top GR Supra as a concept. Dubbed the GR Supra Sport Top, the concept was teased at this year's online-only SEMA360 show last month and will feature a retro-style removable Targa top that was a popular option for the last-generation A80 Supra.

So far, the project has only been previewed in target renderings. Since then, work on the ambitious project has progressed significantly.

In the latest video documenting the car's development, we get to see engineers nervously remove the roof of the Japanese sports car. But since the new Supra wasn't originally designed to be a Targa, cutting the roof was no easy task.

As Toyota Team Manager Marty Schwerter explains, deciding where to cut the roof was "way more complicated than we thought in the beginning." Initially, cutting through the steel proved to be more difficult than the engineers expected. But after a few minutes, the roof is removed and the surgery is successful. It's still a work in progress, but this is a massive step.

When the project is finished, it will have a pair of removable panels that can be released remotely using a keyfob and stored in the trunk. As well as removing the roof, Toyota has already finalized the design of the hand-built diffuser and added a stainless steel exhaust system.

The Supra's structure also had to be reinforced to compensate for the removable roof. Other design features from the Heritage Edition will be applied to the GR Supra Sport Top such as the body kit and the A80 Supra's rear wing. No doubt Toyota will release more videos as the project progresses, but we're keeping our fingers crossed the open-top Supra concept will enter production.