VEHICLE PROGRAM REWRITE SYSTEM, VEHICLE MASTER DEVICE, PROGRESS SYNCHRONIZATION METHOD AND COMPUTER PROGRAM PRODUCT

In a vehicle program rewrite system, a vehicle master device includes a first progress determination unit that is configured to determine a first progress related to a program rewrite, a first progress transmission unit that is configured to transmit the first progress determined by the first progress determination unit to the center device, a second progress acquisition unit that is configured to acquire a second progress related to the program rewrite from the center device, and a first display instruction unit that is configured to instruct to create a content that is displayable on a display terminal mounted in a vehicle based on the first progress determined by the first progress determination unit and the second progress acquired by the second progress acquisition unit.