Sorry, don't mean to call you out...but you do not understand today's vision capture technologies.
They are NOT susceptible to anything surrounding the plate. These systems work in conjunction with enhanced reflectivity/emissivity of the plate itself. The readers/processors can capture, process and alert officers within a fraction of a second, reading hundreds of plates per hour at high speeds, little ambient light.
Very advanced. The only way to defeat the system is to alter the plate in some way...many ways to accomplish this, but most are illegal.
The folks who make toll booth plate readers would salivate for this. Why are they goofing around with character recognition?
PS I know of what I speak about. I worked at a company that did software for toll booths. Character recognition city.