Bedika in Cars - Yechaveh Daat 1:5

In this brief teshuva, Rav Yosef affirms that one is required to do bedikat chametz in his car, just as he is required to check anywhere else in his property where he could logically assume that chametz has been brought. He notes that no new bracha is needed on this bedika, even though there is a lapse in time when one walk to the car. As a concluding note, he mentions that those who drive public buses or planes also have to clean out and check their vehicles.