A hybrid vehicle having an engine and a motor as power sources that generate electrical power, and an output shaft to which driving power from at least one of the engine and the motor is transmitted for driving the vehicle. And a second storage capacity in the first storage capacity which is used to store the data is adjusted based on an amount of valid data which has been written into the storage unit but has not been read from the storage unit. The upper bracket mounts a latch and a belt anchor of a seatbelt system thereon and the lower bracket mounts catch pins forming part of a door catch mechanism operative to prevent movement of the door upon an occurrence of a side collision.