I have a driveway alert. My in-laws have the one from Harbor Freight and they trade it in every year or so when it breaks. Motion detector types don't work for me since the dogs, cats, horses, cows, critters, etc. would set it off. I use the buried magnetic detector. I tried the Mighty Mule and it was intermittent at best. I currently have one made by Dakota and it works wonderfully. Turn the sensitivity all the way up and it will actually go off from someone walking by within a couple of feet of the sensor. It catches a car every time.
Lasts nights storm reminded me of something else about my driveway alarm. Big lightning in the sky sets it off. Smaller flashes don't trigger it, but a big flash does. It also chimes when the power goes out and when it comes back on.