I have now had a response from ADAC, but to be honest am not really any further forward. The confusion (which I specifically asked them to clarify) is in relation to the financial limits regarding roadside assistance and towing costs - the figures they give wouldn't get you very far with prices as they are these days throughout Europe - although they probably would get you to a garage, which is all most would want anyway.
The problem is what happens in the event of the car being completely immobilised and unfixable for whatever reasons e.g. a blown engine or gearbox failure which might require the car bringing all the way back to your home in the UK? The same lack of clarity applies to the caravan breaking down e.g. an axle failure or (as I saw happen in France this year) a major electrical fault when parts could not be sources in the UK for at least a few weeks.
ADAC are not clear in the documentation whether FULL costs of recovery would be met, or any limitations that might apply Additionally, it seems that the 'best' level of service applies within Germany alone - the others are more restricted.
All ADAC has done is refer me to their T&C's - which as I say, do not provide the certainty that I personally would need.
The ADAC Plus scheme, does on paper offer some pretty attractive services, although I feel the lack of clarity would do away with kind of peace of mind I would want.
My current provider 'International Breakdown' - offers this clarity (fair enough it is UK based, and I don't speak German) and more or less all that is covered by ADAC is covered by them - more importantly I know that my car, caravan and passengers will all be repatriated to the UK with full costs met. Costs for this are