This download is comprised of four png images. Three of them are the new Iowa license plate design, one each for Bone County, Flint County, and Red County. The fourth file is a higher-resolution “platecharset”. All files should be installed via a TXD editor in the vehicle.txd file located in /models/generic folder.
The mod images uploaded to GTAInside are the same as the ones included. GTAInside will likely compress these files.
The new platecharset will NOT work in Multi Theft Auto, as the resolution change is not supported. The license plates will still work, however.