Just as one must search his home for Hametz by candlelight on the night before Erev Pesach, so must he search his car for Hametz on this night. Even if one brought his car to the carwash beforehand and had it thoroughly cleaned, he must nevertheless search it for Hametz on the night of the 14th of Nissan by candlelight, just as he searches his home. This means that after one finishes searching through his house, he must take the candle outside into the garage and search through his car. If a person owns two cars, he must search both. This applies even to vehicles that he does not plan on using during Pesach; since they are his property, they require a Bedika just like his home.
Bedikat Hametz is likewise required in all other kinds of vehicles, such as private jets and yachts. In fact, Jewish-owned airlines, i.e. El-Al and Israir, are responsible for performing Bedikat Hametz on their entire fleet of aircraft on the night before Erev Pesach. All vehicles that one owns require a proper, formal Bedikat Hametz by candlelight on the night of the 14th of Nissan.
