The bags are sent out with a letter to people whose license numbers are reported to the Department of Transportation's litter hot line.
The San Antonio Express-News reported Sunday the majority of the offenders appear to take the letters in stride, although a few recipients take the time fire back with letters of their own denying the charges and sometimes taking umbrage at being ratted out by their fellow Texans.
"Maybe you should be checking the people who are making these reports as well," said one miffed motorist. "Get their personal information and see if they like it."
A department spokesman assured the newspaper that the reports are all kept confidential.