After some hard work and many hours of searching there is a tiny light at the end of out tunnel.
Due to the confirmation of the user Stronzo from a different forum I can now confirm that we can use a type of "map sharing" on the Carminat devices:

What you need
Download the program Volume ID from Microsoft : [Only registered and activated users can see links. ] memorise the folder where you put the program
Get familiar with the Dos promt, using
cmd
in the searchbox when you click on the Windows start button.

How to share your map with other users
One word first! This only works for maps activated with a .MCT inside the map folder.
If your map was updated through Home you most likely have a .DCT file for the map activation.
The .MCT is bound to the serialnumber of the SD card, the .DCT to the serial number of your device.
A map with a MCT works in any Carminat, but a map with DCT only the Car it was purchased for!

I assume the SD is in drive E: , if that is not the case use the correct drive letter as shown in your Windows Explorer!
1. Use a cardreader and copy the .MCT file for the map into a folder on your hard drive.
2. Open the command prompt and type:
vol E:
press ENTER
Apart from other things you will get the Volume ID of the SD shown on your screen,
Open an editor and create a textfile containing the volume ID of your SD.
Should be in the form xxxx-xxxx, use the correct name and full version number of your map as a filename to save into the same folder that contains the backup of your .MCT file!
3. Use Winrar and pack both the .MCT and the texfile with the volume ID, again use the full name and version number of the map as a filename.
4. Upload to a file hoster and post the link in this thread.

How to use "shared maps"
Use new SD, not your Original!!
1. Check what maps are already shared by other users.
2. Download the map you like (and that is shared!) from the corresponding map thread and the shared data provided by the user.
3. Unpack the map to the SD.
4. Use Winrar and open the archive containing the shared data.
5. Unpack the .MCT file into your map folder.
6. Open the textfile inside the archive and use the volume ID shared by the user:
Open the command prompt in the folder containing the program VolumeID,
( I again assume the SD in drive E: ,change accordingly if different on your PC! xxxx-xxxx is the volume ID provided inside the rar archive)
type:
volumeid e: xxxx-xxxx
press ENTER
7. Done

Now the new map should work fine on your Carminat!


All this can only work if many users are willing to provide their data, and now, there is no more personal info shared for TT than they would get on any other TT using pirated maps.