I used to tint on the side way back in the days. You need plenty of patience, practice, and quality tint. For the side windows, the key is tinting as close to the top as you can w/no bubbles of course. I had mine tinted professionally and they did the rear window in two pieces. He cut the two pieces (freehand) on top of the line defroster. When the manager went to check on his job, they had to take a spot light to the window b/c they couldn't see where the two pieces connected. Plus, most places have lifetime warranty on their tints so it's well worth having it done.