hi, I would like to seek opinions... i have recently installed a 3M solar film. There appears to be vertical lines from the exterior due to installers spraying some liquid and pushing this liquid out of the solar film - the lines are due to them using a plastic card to expel the liquid. When dried, this appears as vertical or horizontal streaks from the exterior and is very evident when under orange light. Installer claimed that this is normal - may i check with forumers who has such installation if this is the case? Does this apply only to 3M films or films of other make?