That is about as bad as one time when I broke my toe my friend wanted to call a tow [ toe } truck
“Never a bad idea to start recording on your cell phone before he gets to your window, though. Video helps keep people honest.” Also, I was up late one night and saw a paid programming ad for a dash cam. This one is actually a rear-view mirror that straps over your OEM rear-view mirror and it has 2 cameras: 1 for the road ahead and 1 for the road behind. Both cameras can be rotated so you can point one of them at the driver’s side window in the event you are pulled over by the police. This point was made in the advertisement.
As a general rule I think dash cams are a great idea. If anything happens (whether you are involved or not) you have a record to show the police. The down side is, there are so many different types, with prices ranging from about $60.00 to about $500.00 it’s hard to figure out which one to use.
The one I had sure saved my butt! 
You want one that uses a capacitor instead of a battery.