Counter Sank the holes in the rear window to accomodate the dimples in the skin. All the C/S that I've done so far, has been with a normal 3 flute C/S and cage. Works great for me. I always take the carbide stone and twirl it on the edges of the holes to take any burr or roughness out of them, but so far, I've not had any problems drilling or C/S . Aflter prepping the edges I mounted the rear window in place to check the trim line. Attached the main canopy to the frame to mark the final trim line on it. I also tapped all the holes in the roll bar and smoothed it out with some scotch brite wheels on the die grinder.
