I accidentally formatted the card that had navigation working before. It is the original card that came with the car. So, I purchased a new card and copied the contents from the new card and pasted it onto my old card which was formatted but it still says invalid sd card even though it is the card that already had my vin number coded in it before. Doesn't make sense.These chips are VIN specific and are programmed to work for one car and only that car from the supplier (Garmin or Tomtom or w/e we use now). It may or may not work depending on if that is a legitimate card and was never used before (the ebay uncertainty). When it comes to buying these things on ebay its very iffy especially if there is a significant price difference. So bare in mind that if its not a legitimate copy that it may not even work and/or you may not be allowed to update it via the manufacture of the NAV card website. The price is also set by the manufacturer of the cards and are good for 3-4 years. Let us know how this works out and hope for the best. I sure hope you have a way to get a refund if it fails. Also chip, card, same thing. There is a chip in that card so its interchangeable.