the best way i found is to spray the interior with simple green , one area at a time then with suds only(put soap in a bucket and spray hard to produce good suds)scrub the cloth area with a semi durable brush,then take a dry white cloth and press firmly back and forth and watch the dirt come onto the rag,then let air dry..this works good on carpet too,always vacuum first..be careful not to put any degreaser on any item with white lettering as it will dissapear..good luck..on headliners just mist it then wipe off with a clean rag this really looks good...