These forums are the gold standard for Android head unit enthusiasts. Search for "AC8257 XYAUTO firmware" to find community-verified links.
Since there is no single official website for these generic units, you should look in these three primary locations: ac8257 firmware new
Check your purchase history on AliExpress, Amazon, or eBay. Messaging the seller is the safest way to get a file guaranteed to work with your specific screen resolution and CANbus settings. These forums are the gold standard for Android