Ahh, so this makes more sense if you've seen another thread? Consider me confused!<---- just seen the Motorbike Filtering thread and it's all made sense.
OP Fail.
maybe op cut him up / nearly knocked him off and he was having a bad day.. no biker is just gonna damage a car for the hell of it.
i've done the same once to a rolls royce, but only as a last result for revenge after I was physically assaulted at petrol station (he tried to strangle me lol) ...that wing mirror prolly was £800, made me feel a lot better.