From my perspective, license plate numbers are a secondary concern. My primary concern is showing that I've been driving in a reasonable manner.
If I get into a crash and the other party sticks around, but claims it's my fault, then there's no need to have legible plates-- the other party is known. All I need is proof that I was following the rules of the road.
If I get into a crash and the other party drives off, hoping they won't be caught, then I have two concerns:
1) I want the DC to prove to the police and my insurance company that I was following the rules of the road. This takes away my liability for the crash, and means that my insurance rates won't rise as a result of somebody else's actions. But I have to pay the insurance deductible ($1,000, ouch).
2) I want my $1,000 deductible back, for this I need witnesses, or the police to figure out who it was, or I need the DC footage to show plate numbers. Even if plate numbers are available, there's no guarantee that the plates weren't stolen, or the other car wasn't stolen. Or the owners of the other car reported it stolen after the owner crashed into me. So my chances of recovering the deductible are somewhat limited.
In summary, I'd prefer to have a much wide angle coverage to show somebody else crashing into me.
As a side note, it's by choice that I have a high deductible ($1000). If I had a lower deductible ($300), my annual insurance fee would be about $150/year higher. I figure that if I take that $150/year, and consider it my "deductible fund," then I'm doing pretty well: my last at-fault crash was 14 years ago. $150 x 14yrs=$2,100. So I can pay the higher deductible a few times before it's worth having a cheap deductible!