Okay here's an update. After reading more threads on how people were using a ground loop isolator to solve their noise interference problem with an inverter, I decided to try it with my problem with the auto air adapter.
Results? It seems to have worked like a charm, noise interference is gone! The one I used is from best buy for $17.99 although you can find cheaper ones elsewhere.
The isolator has male/female rca plug connectors along with two wires that need to be grounded. I just grounded them to the same place my head unit is grounded.