Please let this be a lesson to all of you. Even those of you who think they would never do this. I am religious about checking my lug nuts after doing work to the car. A few months ago I did the springs and a few other odds and ends. Last night, I started to hear a funny sound from the left rear. I headed to my brothers house nearby to investigate. Two of the five lug nuts were finger loose and the other three were barely any tighter. I have driven the car about 200 miles since I did any work to it. I honestly don't know how I could have left them loose. I check, recheck and then wake up in the middle of the night and go check again.... But, they were loose.
The lessons to be learned are, check and check again. Then go back after a few drives and check again. The second lesson, even more important than the first is to listen to what your car is telling you. Mine saved my life and possibly the lives of others by telling me I was an idiot and didn't tighten the lug nuts properly. It used a click and some strange squeaking to tell me that. If I hadn't been listening, it could have been the misses driving when all hell broke loose.
All is well now and the wheel is fine. I checked again this morning. The bolts / threads were perfect, and no damage to the wheel.
The car is garage kept and never parked anywhere for very long. The only recent exception was a baseball game last week. It is possible, though unlikely, that someone was trying to take the wheels, but I really doubt that. If a pro thief wanted them, she would have taken them.
The moral of the story is: please go check your nuts today!