Many wizards live dual identities, one in the magic world and another in the muggle world. So, they need to follow muggle laws, too. Also, they are protected by muggle laws (they have certain rights given by muggle laws).
Let's say, a muggle court found a wizard guilty because he was making some kind of dangerous liquid (potion) without the necessary authority, what would Ministry of Magic do?
Another situation: A wizard killed someone with Avada Kedavra and went to muggle enforcement for protection. According to muggle laws, the wizard didn't break any laws (nobody can prove that murder having no physical wound, external or internal). What would Ministry of Magic do?
What's the general policy in case of conflict with muggle laws? They can't really initiate a diplomatic interaction with muggle government provided that there's International Statute of Wizarding Secrecy in place.