To determine if your 2007 Mazda6 can use HID bulbs, you should check the owner's manual or contact your local Mazda dealership. Additionally, you can visually inspect the headlights to see if they have HID bulbs installed. HID bulbs are typically characterized by a bluish-white light and a more focused beam pattern compared to halogen bulbs.
It is important to note that HID bulbs require special ballasts and other electrical components to function properly, so simply replacing halogen bulbs with HID bulbs without the necessary modifications may not be advisable. If you want to upgrade your 2007 Mazda6's headlights to HID, it is recommended to consult with a professional automotive technician or an authorized Mazda dealership to ensure proper installation and compatibility.