Incidentally.
If you are living in Spain for 183 days in 12 months then you become tax resident and liable to pay tax on your worldwide assets.
There are certain provisions under the double taxation agreements. Example, a government employee pension (say military or police) is taxed at source and thus ignored in Spain. Income for property rental is also taxable in UK but most other income is taxable here.
But again, you will to check out your situation when you are here.
If you are not working and paying into the Social Services here, you will also need medical insurance as the Euro Health Card is only good for visitors.
And, once to are 'resident' you are not allowed to drive a foreign registered vehicle, although your UK D/L is still OK.