I get it.. F1 and f2 should be used if only 2 sensors in the front. I think that's a good idea, however, I am skeptical if it's worth risking the front to just two sensors when 3 is Jam proof.. Any thought s about that? 95% of Laser hits will be in the front and I know I am risking my rear. BRD I would love to do the same test with two sensors. I am sure you can find one returned or dirty lying around.