The adhesive toll sticker (Austria and Switzerland) must - after complete removal from the backing film - be affixed undamaged and directly to the inside of the windscreen in such a way that it is clearly visible and can be checked from the outside (e.g. not affixed behind a dark tint strip). Sticking the vignette on the side window is not permitted. Special foils, suction cups, adhesive strips, etc. are not permitted for affixing. Any such manipulation will invalidate the proof of proper toll payment. The toll sticker is only valid if it is affixed correctly; if it is affixed incorrectly and you use toll roads in Austria, you will face a heavy fine. 

In the case of single-track vehicles, the toll sticker must be affixed directly to a component that is as flat and non-replaceable as possible (e.g. fork spar or tank) and must be clearly visible. When affixing the sticker, make sure that the surface is clean (remove dust, oil, wax residues before affixing). The same applies to Switzerland vignettes that have to be attached to trailers. (Car trailers and motorbike sidecars do not require an additional toll sticker in Austria!)