The software of automotive equipment grows its scale and complexity. That increases risks to inject defects in its development and find them after shipping. Low cost solutions for software fault removal after shipping of the product are needed by manufacturers. This paper proposes a software update scheme by airwaves that enables automotive equipment to be updated without maintenance work at the factory or user's operation after shipping. In the proposed scheme, the differential binary of the newer binary to the older binary is broadcasted by airwaves, which are used for broadcasting digitalized traffic information to car navigation systems. The automotive equipment receives the differential binary, applies it to the current older binary, and constructs the newer binary. The authors modify implementation of bspatch, a tool for differential binary update on PC, to realize the proposed scheme with considering circumstances specific to automotive use. In more details, the authors introduce in-place update to overcome memory constraint and present a power cut durable software update process to cope with unanticipated power cut by engine cut.