Who does this benefit? The person parking or the person with the parking lot. You will have to get the parking lot guys to get on board with it and this will be your barrier to entry.

Could be a success business! Run with it!

parking app that automatically reads license plates and charges accordingly.

Pretty useful, and great management, esp for people who park on the roadside a lot.

Great use of OCR. I'd love to see this around SF. I'd pitch as: "Automated OCR based billing for private parking lots very similar to Bay Area bridges. Drive in to a parking lot, your vehicle is recognized and you begin to be billed. You leave and you receive a notification of your final parking fee."