In a vehicle on-board reporting system for state emissions tests, the vehicle is provided with a removable media storage device and a radio responder device mounted in the vehicle for transmitting data to and from a remote location. A user interface is mounted in the vehicle and connected to a control module which includes a vehicle identification number diagnostic facilities for receiving data from emission related sensing devices on the vehicle and for determining a malfunction from the received data, an erasable/recordable non-volatile memory for storing diagnostic trouble codes and facilities responsive to a user request for reading the vehicle identification number and the stored diagnostic trouble codes and transmitting the vehicle identification number and emissions information to an output of the control module. The user interface includes a message display and user data entry facilities for sending the user request to read and output the stored diagnostic trouble codes and for selectively connecting one of the removable media storage device and the radio responder to the output of the control module to send emission test data to a state vehicle licensing authority via a recordable media or a radio transmission facility.