We have a Polo, too.
On our T.cross, lane assist could be cancelled with two quick button pushes at start-up.
On the Polo the same applies except an orange warning light appears in the dashboard signifying the function is off. No way around it, either. Annoying!
The digital manual is crap, not a patch on the more comprehensive paper version with the previous car.
If we hadn't had the T.cross with similar functions, we would be struggling setting up the Polo, for sure.
