Couldn't find anything on google about this so thought I'd try here....
I used to have two cheap solar led lights on my shed outside and whenever a bus was parked on the road opposite they would go off despite no line of sight to the PIR. I've since retired them and have a reputable version out from covering a small nook there. A wierd thing happens when 1 particular car passes by, the light turns on, but it doesn't do this for any other car and there is a good 9-10 meter distance. I have to stand within 3-4 meters to set it off myself.
So, question begs what sort of EMI or interference could cause this? Just curious! Thanks.