The 4G card was part of a pre-production specification-it was not a production-approved specification. The 2G card that your system was shipped with is of an optimal size to accommodate your system's maps and navigation functions and has no effect on performance or speed whatsoever. The 2G card is of a size needed to accommodate everything your system needs to work effectively. Nevertheless, we are happy to honor pre-production statements pertaining to the 4G card by replacing your 2G with a 4G card if you bought your system prior to September 14, 2007. However, we strongly discourage its use in other devices as this may result in damage to the data contained on the card.