It is now possible to pay for Austrian tolls with a software tweak to a German On Board Unit (OBU).
More info HERE
When the German OBU is recalibrated, the Austrian Go Box registered to the vehicle will be deactivated and should be returned to an agent.
I’m off to Austria tomorrow with a bag full of all our firm’s Go Boxes…
Well, that was painless.
Go Box cashed in and now using the German OBU to pay the Austrian tolls. The OBU beeps in the same way as the Go Box when going under a toll gantry (1 beep: OK, 2 beeps: wrong number of axles, 4 beeps: Die pig dog!)
Obviously not for bods who revel in having their windscreen full of toll boxes to compensate for their inadequacies in the wedding tackle department, however 
Oh for the day when the one box works the whole of europe-including the UK