BLE proximity alert.

Hi, I am looking for someone who can help with my kid's project. we want a compact module that can detect another module of the same design to put on a remote control car to turn on a led mounted on top of the car when it comes close to another car with the same module. basically, a proximity alert system that reacts when it comes within a set distance. for example, if car A is driving around and comes within 50 meters of cars B, C and D then all cars A, B, C, and D lights will flash until they leave that set distance of 50 meters but all the other cars beyond A, B, C, D won't alarm if they are outside the proximity.