@japchap Once upon a time car registration labels were adhered to the inside of the windscreen. The initial run (of several decades) was a type that needed to be soaked in water to activate the adhesive. Once dried it was very hard to remove and had to be replaced annually. These were discontinued and the next lot that lasted about 15 years were self-adhering. Both type were very hard to remove easily but eucalyptus oil just sucked the life out of the glue and they'd come away easily.