Report it. Last year we had driver in my area who was repeatedly harassing and intentionally driving at cyclists. After enough incidents were reported, the police in several towns compared notes and were able to track the person down and arrest them. No slam inferred regarding how fast the police responded; my point is that it took a while to collect enough data (vehicle descriptions, partial plates, etc.) to finally get the person. After the news broke, more people came forward with incident descriptions. Don't expect a flurry of action based on just your report, but if the guy who took a run at you is in the habit of targeting cyclists, maybe your info will help track him down.