Pull up the two front seat headrests of your car as high as they will go. Measure the outside distance between the headrest posts with the measuring tape. This is the measurement you will use to cut the length of the pre-drilled angle iron.
Cut the pre-drilled angle iron to length with the hacksaw. Cut carefully and try not to create a jagged edge. If you do make a jagged edge, file it smooth with the metal file.
Place the angle iron between the two headrests. Make sure the angle iron rests flat against the headrest posts. The angle iron should rest against the headrest posts in an inverted "L" shape.
Attach the angle iron firmly to the headrest posts with the four cable ties. Cut off the excess length of the cable ties with the wire cutters.
Push the two headrests back down to help lock the mount in place.
Line up your camcorder's tripod screw hole with the central hole in the pre-drilled angle iron. Place the large washers on the 3/4-inch bolt. Screw the bolt through the angle iron and into your camcorder's tripod screw hole.