In this video I show you how to cut a perfect circle for your car audio install:
What you need:
Router (Preferably a plunge, but I show you can use a normal one)
Jasper Circle Jig
3/16 Drill Bit
Wood to cut a circle into
The Jasper circle jig in the video is the Model 200. Search Google for "Jasper Circle Jig Model 200" to find it.