How to run and own a UK car in Europe?

[Steve the Light]

Please could anyone help here?
Over Christmas I drove my V70 over to Spain and left it at a Spanish airport close to the French border to use it as a run-around for most of the year. What's the best way of dealing with Tax and Insurance?
My situation:
The car is registered as a UK (right hand drive) vehicle at my home UK address.
It will spend the next 9 months of the year in the Spanish Airport car park.
We intend to fly in and out of Spain and drive from the airport to our French property and back to Spain once every 2 to 3 months for 1 to 3 weeks at a time.
We would like to drive it back to the UK around October to MOT it and will drive back to Spain next December.
I have full (10+) years NCD on my UK insurance which is about to expire

How should I insure it?
Do I SORN or Tax it whilst it is outside of the UK?

So far I have discovered that:
I cannot find UK or French insurer as the vehicle is out of both countries for more than 6 months of the year.
I cannot find Spanish insurance because I have not got an address in Spain.
I do however know someone who is happy to allow me to to use his Spanish address (700 of miles away) to give to an insurance company, but I have never been there, or have any connection with it. The Spanish insurance company say they can use my UK address for correspondence but need a Spanish address to register the policy. Would this be legal? would there be any issues that may affect the owner of this Spanish address for any reason, particularly if I had to make a claim?
Thanks for reading.