Review on 🔑 BINOWEN Mazda 3 Buttons Key Fob Shell Remote Case Replacement with Folding Uncut Blade - Fits Mazda 3 5 6 RX8 CX5 CX7 CX9 Keys - The Best Option by Larry Morris

If your car needs a transponder (most do) you can't just cut the key and drive. You'll need to replace all the guts including the transponder chip at the top where the key is supposed to get your new key working. FYI, if you just need a new case because your old one is falling apart, this one will do. Replacing the internals is easy for the bottom, but the top with key, transponder and spring is another matter. I used a YouTube video to include all the guts. Took 20 minutes, the spring is a pain, I would recommend using the original spring from your OEM FOB, it's stronger. I spent an additional $5 at my local key store to get a key. I saved a lot of money by doing this work myself.