The Toyota is what did the crashing. Not all verbs are action verbs. Some verbs are linking. These are verbs like am , is , are , was , were , seem , and become , among others. Linking verbs connect the subject to something that is said about the subject.
Bathroom is the subject.
Is connects the subject to something that is said about it, that the bathroom is a disaster. The word tiles is the subject. Are connects tiles to something said about them, that they are fuzzy with mold. Generally, but not always, the subject of a linking verb will come before the linking verb. Know the difference between a complete subject and a simple subject.