Instead of a conventional steel body, the Opel Maxx had a stable light alloy structure made of extruded aluminum profiles like a cage, which was visible from the outside.
The form and dimensions of the profiles were variable, ensuring exceptional flexibility.
The idea behind it was that instead of the two-door and two-seat basic version, Opel was also able to build a four-door extended version with four or even six seats.
Source: www.carbodydesign.com