Advice from the police after getting buzzed.
Sunday I was riding down a stretch of familiar road and got buzzed by a mom mobile. I was doing about 10 MPH while as FRAP on a 4 lane section of residential street, and got passed by someone about 1 1/2 feet at the most away from me. Ordinarily this doesn't happen and I try and let things not bother me when I'm riding but this was worse than usual - bad enough for me to decide to call the police when I reached my destination 5 minutes later. I'd memorized the license plate number and gave that to the 911 dispatcher figuring that would be the end of it, and instead I ended up talking with a cop about what happened. He said the best thing for me to have done then would have been to call right away while the car was in the area, this way they could have stopped them if they saw them and talked with them about what happened. Since I'd waited they couldn't do much more than call the person if there was a phone number listed with the license plate (and that's all I wanted them to do).
So if you're wondering if you should call or not make the call soon according to the cop I talked with if you want to increase the chances of something positive happening - or get a camera.