Giorgetto Giugiaro took a floorpan and bolted several different bodystyles onto it:
ID Formula Hammer
First it was the Formula 4 introduced in Geneva. It's a doorless roodster
Virtually any detail should be screwed out and replaced with another. The bare shell looks like a "Lego-mobile".
Next came the Formula Hammer which was introduced in Turin, late May.
The Hammer is also doorless, but it is aimed to be a leisure car, almost an all-terrain vehicle.
The donor remained the Bravo. There are no doors, only side openings, so instead of jumping into the car as in the roadster, they can easily sit in.
The interiors assembled to the mechanised floorpan are the sames as for the Formula 4.
Another matter which matters heavily in the these kind of machines is safety. Look at the Hammer: to the rear, there's a rollbar which may be split into two on request, as on the F4.
Two single rollbars may also be attached on the side of the car.
The sill as it is higher than the H point, the sill protects passengers in the event of side collisions.
Another Formula variant was also presented in Turin: it's the Legram. It took cues from the Daewoo based Bucrane of last year, but it's now based on the Bravo(a).
Some think Giugiaro missed the point. I also think that to store 5 different bodies in a garage and choose between them as the weather changes is kind of weird.