Back to the original question about bright lights, the car behind you may well have been driving on his daylight driving lights, which is technically illegal in restricted visibility conditions, i.e night, fog or other serious weather conditions, specifically because they are not angled down and will dazzle other drivers. Short of starting a road rage incident by forcing the other driver to stop, you could try taking the number and reporting it to the police, or my personal preference would be to fix a torch or other light to your rear rack operated by a button on the handlebar, and see how he likes it with a beam shining in his eyes.