So one simple tip is too use a piece of masking tape and use this to tape the wiper up, so it leaves space so you can still shrink the window film without fear of the wiper dropping down and hitting the film. i made a quick video showing how to do it – its simple thing buy maybe one day you will be able to use it. Be aware that on some cars, you may need to remove the rear wiper and even the rear wiper motor assembly to get the job done right, cars that spring to mind here are the Mk 1 Honda CRV and the Mitsubishi Evo. On these cars, by leaving the wiper motor spindle in position will make the job a real pain and the few minutes it takes to strip it out will save you a lot of heartache.