cheapo chinese

Hi, I have an xgody 704 which, despite being very cheap, is actually quite good. I have a few irritants such as settings don’t save so you have to turn off speed warning every time your turn it on but more importantly it seems impossible to update the maps on naviextras as the device is not recognised! Surprise, surprise!
So really, as a newbie in all of this, I wonder if it is possible to download and install maps from another provider to this device.
Any thoughts welcomed! 🙂