I stopped at the local HomeDepot this afternoon, when I got out of my truck I did like normal and hit my key fob lock twice while walking away, and heard two horn honks. Turned around to look at my truck and hit the button twice again, my truck honked and a GMC about 4 spaces down honked. OK were on the same code. As luck would have it the owner of the truck walked up and started loading the bed, I couldnt resist hopping in my truck, firing it up then hitting the key fob lock and unlock buttons a couple times. Poor guy couldnt figure out why his truck suddenly started locking/unlocking and honking at him. Cheap fun.