I use a Passport 9500. I rarely get a laser warning, and as far as I know, I've never gotten a false positive warning (although there have been a few times where I never did spot the source of the laser). If there were cars using lasers that confused the Passport detector, I'm sure I would know about it by now!What about other cars. Other manufacturers started using lasers over 20 years ago. I don't know if they still use such systems, but I'm sure many of those cars are still on the road.