We're they just for competition Melle, only seen them on SAABs rally cars, where they stronger than the usual soccerballs!? They look to have a different design!
Don't know if this has them on, just a nice pic of a 96!
Saab found that they original soccer balls broke up when rallying with them. Possibly when used on the Baja race? They found that by machining them in a certain way it made them lighter but also allowed them to flex, which stopped the breakages. That's what I've read and it sounds reasonable. Mind you, Saab might have had special forged alloy ones made before machining them.