The exact location of the access panel varies slightly depending on trim level and options, but it's generally located in the rear floor of the trunk, often covered by carpeting. You'll likely need to remove some carpeting and possibly some trim pieces to access it. Look for a section of the trunk floor that seems slightly different, maybe with some screws or fasteners. A shop manual or online repair guide specific to your year and model Talon will give you the most precise location and instructions.