All, after reading through the posts here I decided to try something and so far it is working. What I have done is place a small snoot (tube) made from tape over the PIR sensor under the lens. This keeps the range of the sensor focused on a small area directly in front of the camera. It doesn’t affect the view but so far today it has eliminated falsing from cars going nearby and for the afternoon no falsing so far at all. I was actually able to turn the sensitivty up to 6 (it was on 3) and now when someone comes up the stairs to our place it will go off as soon as they take the first or second step. It also allows us to open our door without setting off the sensor until we step out of the doorway.
The snoot I made is kind of crude but it seems like it would be something easy to make that could fit on any of our cameras. Here’s a photo.
Some photos of the area it is installed. From inside our door and from behind the camera showing where it is looking.