Has anyone managed to be successful in activating the driving instructor mode on the swing radio unit via VCDS? I activated it on VCDS but cant find to get it to appear on the swing unit itself. And does the speed appear next to the outside temp and time?

I tried this on my 2012 bolero coding, selected driving school mode which should display speed on the HU. Made no difference, must only be available on certain HU's.

Correct, only certain headunits support this feature and it usually needs an additional activation using a special button combination or a tick in the setup menu.