Why are there bubbles in the dot matrix of my 2007 BMW 328?

Method 1: If you’ve tinted the back glass of a 2007 BMW 328 and there are bubbles or streaks in the dot matrix, it’s because the matrix wasn’t prepared enough before installation. This means that it won’t completely adhere to the film. Some dot matrixes can be roughened up with a razor blade, but use sandpaper and a scrub pad to prepare this model. Elmer’s glue is also commonly used to get the film to completely stick down.    Method 2: Another technique is to install the film all the way from the bottom up until the beginning of the dot matrix, then just let it hang. Let it dry while you do the other windows (if you need to do them). Once it has dried, come back with a hard card and a paper towel and push the film evenly with your card and paper towel. This technique is harder in cold weather but in the right settings can help you avoid the need for sandpaper or scrub pads.