For the board that is to protect the engine ignition system etc. from water and is located at the lower rear of the vehicle, as the shape is improper, it may allow rainwater to enter the inside of the distributor through the air vent when the vehicle is driven on the motorway etc. for a long time. The rainwater can remain inside the distributor, and if the vehicle continues to be driven in such a condition, at worst the ignition system may fail, in which case the engine could stop and will not restart.