Hi there! My name is***** would be my pleasure to assist you with this. upgrades are available through the purchase of an SD card directly from the company. You will need to visit Nextar.com to order the USA and Canada Maps Update. You will need the model number (which you've already provided - q4 x11-15302) and serial number (for certain models) to find the compatible card. You can usually find the serial number of your Nextar GPS by looking on the back of the unit or on the box it came in. Check the overview description to see which SD card lists your GPS model number and serial number and order the matching card.
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