The one-off front electric sustainer for the Lak 17 needs three things
to do, as I understand it, and I believe will be incorporated into the
factory-fit version of when there is an official modification to do
so:

Open fresh air vent, if not already open;

Switch on;

Rotate dial to speed required.

See http://www.front-electric-sustainer.com/

And: http://www.front-electric-sustainer.com/video.php


Chris N