Weird business idea of the day

Google (and other companies) often provide this "your lights are on" registry -- you put in your car's license plate number, and an email address, and if somebody notices your lights are on, they can put in the plate number and the system sends you a message. The important features of this system are:

• Random people can't determine the mapping between license plates and people.
• When you send a message through the system, the recipient finds out who you are.
  

So here's the idea: I want the police to provide this service, state-wide, for everybody. They have your name and possibly phone number already. You can also opt in by giving an email address. For $5 you can send a letter to anybody addressed by license plate. $.99 for an email or SMS message. Some messages like "lights are on" would be free.

The system lives at a well-known number so you can send a text there, with the first 7 characters being the license plate, and it forwards the body to the recipient and charges your carrier.

Business model is for "missed connections" while driving, or the various cases where you'd leave a note right now -- like "I saw somebody hit your car", etc.