I sincerely doubt you will get anywhere with the police I have lived here over 15 years and never got a policemen to do his job in any respect. I am sorry to say it is mostly Qataris that run people off the road flashing lights etc. I do have a bit of a solution it worked for a friend in Kuwait its rather radical and silly but it helps. Wear a headress like Qataris they still bother you on the road but not quite as much. Myself as a women have almost thought to do it just to see if I get a different reaction. My husband is Qatari and we had 2 Qatari women the other night flashing their lights trying to get us to move, we only do so if safe. At least since we didn't move they didn't then throw themselves in front of us, this is a very Macho thing to do like to prove their superiority. There used to be a time only Qataris would behave badly on the roads but now I find all nationalitys making me crazy. I am finding Qataris are getting as arrogant as the Kuwaitis there seems to be a correlation between an increase in wealth seems to mean an increase in arrogance. I have taken down many license numbers but never got around to pursue it, I think Brigadir Mohammed Al-Malki might listen! Good luck and play it safe and stay alive.