I have similar experience. But I at least horn for 1-2mins
non-stop. Plus car behind, cannot reverse. Anyway, taxi-driver just
got out and see. No damage done, because it is a light kiss.
But from what I read so far, the one behind usually is deem at
fault. So if no-car behind you, reverse the hell out. Or don't stay
to close to him. If he engage wrong gear and ram into you. Come out
take pictures immediately, paying attention to the tyre marks of
both cars.
Conclusion, always keep your camera ready and in ease of reach.