Leaf Sat Nav Headunit

All
I am a newbie here having just bought my first Leaf which I love. It does have 1 bizarre fault. The head unit works fine in switched on mode and when driving. However when the carsnpoeered down the front tilt panel opens closes continually until the 12v battery is flat. I have tried a couple of fixes on google to no avail. Clarion want £850 to fix it. If I buy a second hand unit with the SD card for that unit will it plug and play or is it in some way tied to the car. Has anyone any experience of this please.
Much appreciated in advance.
Landmerc.

You might want to tell us which MY Leaf...and your location (which I suspect is somewhere in Europe).
What you propose is possible, but I'm not sure if the SD card is just tied to the unit or car (or both)...assuming you don't have any warranty recourse.