 Similar to the trend set by Mattel's Hot Wheels, and as a cost saver, tires were hard plastic, though wheel designs were often unique to the particular model, a feature that Solido had pioneered in the 1970s.For example, Audi's four "Auto Union" rings appear on Schabak wheels.Schabak, perhaps more than anything, is known for its diecast airplanes, mostly commercial airliner models in .