Shita: A Deadly Silence (2004)

Original title: 舌~デッドリー・サイレンス

A man, living in a humble apartment with his young wife, accidentally pushes her and kills her. The guy is panic-stricken, and first he tries to hide the body, putting it in the trunk of his car, then he realizes she's "some way" alive (a "living dead" form of life), and she even helps him to kill a cop... or is it just his sick imagination?