Magnetic signs on cars are an interesting usage of technology. Though it looks like someone had fun with these ones.
I came across this real estate agent’s car parked in the Enmore. You can see what look like a business card stuck to the car door, though up side down. Close inspection showed that the label was one big magnet.
It looks like a good way to have one car that can be easily customised for whichever real estate agent needs it. Unfortunately it also leaves room for people to play with.