The invention generally relates to vehicle diagnostic systems and their methods of use, and more particularly, to a hand-held automotive diagnostic code-reader/scan tool with data link connector (DTC) which straps to the user's arm and is comprised of a touch screen, a VIN bar code/number scanner, a credit card reader, a printer, and internet and cell phone connections to a variety of servers for credit card approval, billing and vehicle diagnostics. The credit card is scanned and billed followed by scanning the vehicle VIN number or bar code and sending the information to the vehicle OBD2 server who identifies the vehicle, orders the handheld tool to perform certain tests upon the vehicle and in turn performs a diagnosis. A live wireless cell phone connection may be made, if necessary, with a technician at the OBD2 server for tech support. Test results are returned to the hand tool which prints out the results, prints a credit card receipt and sends a record of the transaction to the operators server Corp. for record keeping.