Well, I read some of links that catymag hade on his post and it looks like I´m on right way to solve some of my questions.

Since Lane Assistant is included in .img file it makes my work much more easy then before.

As I understand I can have a JCV folder on my Garmin folder on my SD card.
So now my SD card looks like this:

Garmin (SD name)
Garmin (folder) with .img and. xml and JCV folder
JCV folder includes one file, D2504080A.JCV

but it looks like D2504080A.JCV doesn´t work with Europe 2013:20, since D2504080A.JCV is 2013:10.