If you buy a smartcard on ebay, whether it is new or used, programmed for another vehicle or unprogrammed, you can still program it yourself for your vehicle (assuming you already have 2 working cards). If you go through eBay like I did, I would highly advise on going with a new card and not a used one. I bought a brand new one, and all it took was one 4 foot drop (by the Mazda service manager) for it to stop working properly, so if you buy a used one, you don't know if it's been dropped or disassembled or what. Also, just for fyi, if a smartcard on eBay does not come with an aux key, or comes with a used aux key that is already cut for another vehicle, you can buy an uncut aux key on eBay, or other website, or through Mazda, I think they're like 30 bucks through the dealer. Just beware: "They" are selling alot of knock off aux keys on the internet which look like the real actual key, and does fit in the smartcard, but does not fit as nicely as the genuine Mazda aux key, and additionally, and most importantly, some of these guys glue the transponder chip inside the square key housing with one tiny dab of glue (likely comes from China). If that transponder chip falls out of the key, and for whatever reason your smartcard goes dead and you need the aux key as a backup, your aux key will not let you start the car if the chip has fallen out somewhere along the way. My advise: IF THE AUX KEY YOU OBTAIN WHETHER IT BE WITH THE SMARTCARD OR SEPARATELY DOES NOT COME DIRECTLY FROM MAZDA, BE SURE TO CONTACT THE SELLER AND ASK IF IT IS AN OEM MAZDA KEYBLANK, KEYBLANK HOUSING, AND KEYBLANK TRANSPONDER CHIP, because these guys are selling new oem Mazda smartcards, with knockoff aux keys that are cheaply made.