Have been considering a driveway sensor for some time. (Should have grabbed the one posted several months ago...) I think the Cartell CP-2 is one of the better ones but I forget how much solid data I had for that - it has been a while. I did some looking around and there seem to be a couple similar ones. I want a wired, buried one that works on magnetic fields. I think they should be much more reliable than IR ones. How do the Mighty Mule FM138, Cartell CP-2, and Dakota alert VS-50 compare? Anyone have experience with any of them? I at first thought the Dakota alert P-50 would be a lot cheaper but then figured out that is just the probe and requires a control box which the VS-50 includes.