You cannot use a mapped-superclass in the query. If you want to use Automobile
in the query, don't mark it as mapped-superclass, instead mark it as an entity.
Following is from the JPA 2.0 Spec, second paragraph is what's relevant in your case -
2.11.2 Mapped Superclasses
An entity may inherit from a superclass that provides persistent entity state and mapping information, but which is not itself an entity. Typically, the purpose of such a mapped superclass is to define state and mapping information that is common to multiple entity classes.
A mapped superclass, unlike an entity, is not queryable and must not be passed as an argument to EntityManager or Query operations. Persistent relationships defined by a mapped superclass must be unidirectional.