Installed new security camera at my firing range which, when triggered, sends RF signal to start DVD recorder. Neighbor,1/4 mile to the south,had his remote starter activate on one of his cars several times. As he knows I have quite a few RF items he mentioned his problem. I checked his receiver frequency and it was identical to my camera. Changed board in camera xmitter to different freq, problem solved. With so much more RF involved in homes, is cross contamination becoming a problem?
It's certainly something to consider. It's probably best to NEVER leave things at their 'default' or 'factory' settings.
I installed several ceiling fans in a new house. A remote used in one room would often operate fans in several rooms. Changing the settings fixed that.
I was being awakened by my doorbell at the strangest times ... and no one was ever there. It turned out that a paralyzed neighbor was using the same sort of cordless doorbell to signal his nurse. Again, changing the DIP switches solved the problem.
Apart from the old analogue cordless phones, and perhaps a cheap doorbell, I would have expected decent remote control systems to use a digital code to avoid mis-operation. Going into a car park and finding someone elses car unlocking I think very unlikely. It's certainly never happened to me. This isn't down to (just) the frequency, but the need to match the preset code. I've heard stories of car control systems being blocked by powerful transmitters nearby, simply overloading the receiver, but never of actually operating due to the interference signal. Is it really a remote start on the car? Sounds potentially dodgy to me! Certainly ought to be protected from operation by stray RF signals.
I once worked for a company that used the bosses home as our shop. His cordless phone picked up the baby moniter. We listened to a couple of nooners before he figured out which nieghbor it was and told them he had there baby crying or some bull(lol)
My son-in-law obtains most of the receivers/transmitters that I use around my property. He obtains most from, or through, a company in Enfield, UK. He tells me that the electronics are far superior to the domestic products. In support of this, I have had 0 failures of 17 items with anything he has obtained but 3 failures of 11 w/domestic. My cell phone still causes squealing in my NuTone intercom system if I get too close.
Once, I was at my mother's house, I locked my Camaro with my key FOB and my mothers' Chrysler 300 unlocked. Only happened once, though. The rolling codes just happened to be the same at that instant, I guess.