A friend of mine has a camper van the he and I built. It has a boot box that he converted into a power station, and he is now upgrading that battery bank. He needed the front opening to be larger to accommodate his new gear, and he asked me for help. There are several ways to do this, however, using a router has some advantages. Notably, corners look cleaner and when using a plunge bit you get a much nicer finished edge. Below is a little tip that will easily allow you to make your cuts in a straight line.