I was fined a few years ago for not having credit to pay for a tyre breakdown call out.Normally i carried a spare.On this occasion,the Guarda Civil policeman asked me if i had a visa/credit card,suspicious of a scam of somesort or trumped up charge,i replied no.Then got nicked.When in the UK i challenged the fine to Spanish consulate,they only acknowledged receipt of the money,and not challenge of having credit or a spare tyre.I had a credit/visa/DKV card on me when he asked me.He then went to the bar to celebrate with his mates,with a drink or two.And laughing at his triumph.Any takers on this. 
Quite simple really, its illegal in Spain not to carry a spare or not to have funds to pay for a call out, you answered your own question Toby.
Normally the DKV card would have sufficed and no fine would have been due.
You seem to be a walking disaster zone Toby. Have you been driving long or are you living in a wibbly-wobbly-jellybaby-world of your own?
If you run Spain all the time - and from your stories you seem to be there, or at least fined alot there - the police must be making a special trip out to ‘see you across their patch!’
Perhaps it time to be beamed up to your home planet!
i was thinking the same plambert 
If Toby’s exploits don’t scare people out of doing Europe, nothing will.
I am eternally grateful that in the years I have been driving around Europe I have only fallen foul of the authorities a few times, but nothing major,
just speeding in Spain, fair cop (25000pts).
one overtaking offence in Germany 40DM,
not wearing a seat belt €60
and a tacho offence that cost me €140 caused through a fault with the head unit…
there may have been a couple of other very minor coffee money offences, but I won’t count them.
I think if I had Toby’s luck I would have gone skint and given up the continent years ago