I've found a way how to implement it in Mk4 systems. Modified software will query map database for POI around car location with regular time intervals. If one or more POI of specified type found, system will emit voice message.
Arguments for and against:
- Alert POI will be stored directly in carindb database
- Alert POI will be always visible (instead of city centers)
- Map query interval can exceed 3 seconds during map scale change
- It does not matter what road you're driving then approaching alert POI
Is this feature really necessary ?
I need to know it before writing POI converter.