I had one for 18 months. It was wired wrong from the beginning, and I spent 6 months fighting with the company that put it in to fix it. I also had trouble when it didn't work properly, because it meant I didn't go anywhere. I cursed the thing many times. If it got too cold, it didn't work. If it got too hot, same. I had to keep it out of the sun in the summer, and wrap it in a towel during winter, when not in use. False positives are real. Hand sanitizer is a bad idea, in my experience, along with things others have mentioned.