My vote goes to TAXIS...
I don't mean to stereotype all taxi drivers...but I swear they all learn driving from the same school and goes by the same rules:
1) Stop abruptly when you see a customer waving for a taxi along the road, regardless if there are any cars behind;
2) When filtering, do not signal. At most 1 flick of the signal when absolutely necessary, but make sure your vehicle is already halfway into the other lane when you do so.
3) When you see another vehicle signalling coming into your lane, speed up and close up the gap. Make sure you do NOT let the bugger come in front of you.
4) Flash your high beam when there's another vehicle in front of you (regardless of how fast he's going).