The object was first spotted when leaving the motorway at Cossonay by car. The object was hovering in what seemed like circles. The two witnesses were first surprised by the sheer size of the object (pretty big considering the distance) and the fact that it could change both direction and color (from black [20% of the time] to reflective)The object was followed for about 30 minutes from Cossonay to Vufflens-la-Ville. When we left Vufflens-la-Ville, the object could not be found any longer in a 5 min timespan, at which point we stopped looking for it.