Having not lived in England for 14 years I am out of touch with the current situation, so don't shoot me down if the following is the norm:
Here in Spain we have an emergency contact system that is very simple. In the event of an accident etc. the emergency services will use your mobile phone to find your next of kin or whoever is listed under AA on your phone i.e. in my case it is AA Jackie. obviously listing the AA would be problematic, but that doesn't apply here because breakdowns are covered by your insurance company.
With many motorhomers spending extended time here it occurred to me that this simple method may come in useful in the event of something unfortunate happening,and by adopting the Spanish system even temporarily while on holiday,may be helpful, hopefully just for peace of mind.
Phil