What state are we walking about? There IS case law that exists specifically on the issue of hanging air fresheners out of the 9th Circuit Court of Appeals.
In short, the arrest would have to have been for probable cause. If the obstruction of view is a violation in your un-named state, then the detention will likely be lawful. After that, the cause for the arrest will have to be based on factors you have neglected to advise us of.
- Carl