How do you manually update the software or check if there are updates. I've checked through the menus but cant see an update function.

The old way was to input your VIN into the website and download to a SD card.

My current software on the Columbus set is 1788 ,, is that the current one?

 

As far as I know Infotainment software updates are downloaded automatically and you get a notification once they are available to install. 

I have 1788 version. But after two automatic updates version is still the same.

 

Even after the update of two computer modules (kessy and clima) at the dealer, version didn't change. So I'm not sure when version changes.

 

Dealer confirmed currently there are no other updates available for my car.