No, they usually don't kick down someone's door, at first. They usually notify someone in writing  If they want to do an audit, they usually ask in writing for the tax payer's cooperation. The only time they are going to kick in a door is when they want to arrest someone for tax evasion (I believe the FBI actually does this) or they are seizing someone's property. However, a person's case has to be rather far advanced for them to resort to such extreme measures.