Can't do screen shots, but here's a description
Click add macro
Under triggers...
Click connectivity
Click bluetooth event
Choose device connected, click ok, choose your Golf's bluetooth device name (VW BT xxxx)
Goto the actions tab
Click connectivity
Choose hotspot on/off
It will prompt that it needs permission to change that
click ok
Toggle the permission
Go back, choose hotspot again, ignore the warning with ok
Choose enable hotspot and ok
click the tick button (bottom right)
Give your macro a name (eg car on)
Add another macro, repeating the same, but choosing disconnect bluetooth and hotspot off, save as "car off".
Job done!
Takes about a minute to setup!