MS-13A, MS-14A Motion Sensors

[gary]

Does anybody know how to reduce the
sensitivity of the these motion detectors
so they do no pick up cars on the street 40
feet away from my home? I only want them to
detect cars pulling in the driveway and not
passing by the house. I could rotate the
sensor 90 degrees so it only sees my
driveway and my neighbors but my neighbor
has a constant traffic in his driveway
which is almost just as bad.