You don't need to capture the plate to show what happened. In fact I don't really worry much about capturing plate numbers these days since few cameras can do it reliably anyway.

I started riding with rear facing one day when after a close incident I realized that front facing video would have made it look like I was at fault.

I was riding right of the fog line on a very wide shoulder over a freeway overpass. There was an emerging right turn lane carved out of the shoulder on the far side. As I got well into the onramp lane (still to the right of the traffic lane) I looked in my mirror and saw that the car behind me was moving to the right, and was about halfway off the lane and into the onramp lane. I assumed he wanted to get into the entrance ramp, so I moved left into the traffic lane.

Then the idiot looked up from his phone, realized he had drifted way out of his lane, jerked back to the left, then laid on the horn at me for being "in his way"

I realized that if I had been hit, the front video would have shown me moving left into traffic lane and then getting hit, clearly not the whole story.

That's when i started looking for a rear camera.