Be sure and remove any of the polishing/sealant products that you may have applied to the glass.
This is a fluro-carbon resin, not a dimethal, and the glass must be "CLEAN" in order for the resin to attach to the glass. Any oil or waxes present, dirt, etc will affect the attachment.
While you are cleaning the glass, clean the edges of your wiper blades, you might have more build up on them than you are aware off. This can abrade the film of the product you are applying.
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