Only really had it happen once. I was going on a ride in Fruita with a group. I walked out into the parking lot, pushed the button on my car and got the Call of the Wild Subaru, just as the same Subaru chirped right next to mine with the identical 1998 Stumpjumper Pro on top of it. Same color car, same year, same model with identical roof racks and identical bikes.
Frankly it was a little creepy.