What type of crime is your main target? Do you store video in addition to plate numbers? How accurate are your speed estimates at oblique angles?

I think you are getting some pushback because a lot of neighborhood watch groups have a reputation for looking out for "wrong looking people." The Trayvon Martin case surely didn't help, either.

Also, crime in the US is an all time low, but perception of crime is at an all time high. This is good for your product, but not for our society.