I think if I can catch the vehicle from the front I'm hoping for a heat signature that will give enough of a difference to make an alert.
I just had a lot of trouble getting the detector to react at different light levels on some simple arrangements in a closet. Tried all sorts of things and kept getting weird reactions. The fact that there are several different entries for each motion detector rattles my feeble mind! As I think I indicated before, I'm fairly new to ISY and still trying to figure out some of the programing.
What I would love is some more programing detail on the actual concept that I'm trying to do. I've seen old posts saying I'd need several different programs and variables and things I really don't understand. If Motion 1 is switched on, Then motion 2 switched on, send signal to alert.......is what I think I 'm looking for but just can't seem to get it down right with delays etc. I'll keep playing. I'm surprised someone hasn't written one that's simple.