IIRC Traxxas transmitters have this useful feature (for tracks that rent R/Cs) where you can bind one transmitter to multiple receivers AND one receiver to multiple transmitters. Then, when you turn a TX and RX on at the same time, they find each other and link together. This way, you don't have to keep track of which TX goes to which RX; just grab a transmitter and a car and go.

Are there any other brands that have a similar feature?