Yes I have a few of those and absolute spider magnets. But on the newer Dahua bullet style, you can pull the sun sheild all the way back and I think it helps. I am having better luck on the 1831 having done this.
The other problem with bullets, they can be moved fairly easy. The pic with the kid telling us that we are number 2 was the original position, the next pic was just after they moved it. Needless to say, the cops where already called for this makeshift car show that popped up out of no where behind one of our customer's warehouses.