To register a UK car in Spain???? It's probably easier to get an invitation to afternoon tea with the prime minister.
A gestor will do it for you for about 1400E. Our daughter, who is fluent in Spanish having gone to school there decided to do it for us. She also thought that once she had done ours, she might start up a little business for ex pats to do it a bit cheaper than through the gestor.
However, although it cost us only 350 Euros through our daughter.....in her words, she was "ready to wrap the Spanish plates around someone's head" by the time it was done and she would NEVER EVER do it again, not for 3000 Euros!!!!
First of all, we had to meet up with some dodgy character who was a "vehicle examiner" (arranged by the tax place in Malaga) in Ikea Car Park (Yes....Ikea car park.....and the official tax office put us in touch with this bandit). We met him, he examined the car, did a lot of tut tutting & said this that & the other were not in order but if we paid him 300Euros in cash, he could sort out the paperwork & then we could apply for our Spanish plates. ERrrrrr.....Did he think we came in on the last banana boat???? We told him "No" & asked our Spanish neighbours what to do. They "knew someone" who was a vehicle examiner. We met with him over a beer & he did the job for 50 Euros and gave us the Certificate to say our car WAS in order.
I would say about 10 journeys to & from Malaga from our home 40 miles away....each time, you need this extra paper, that extra paper (why they can't tell you what you need at the beginning????). We were told that, having proved that we had the car for more than six months & some other stipulation which I can't recall, we would not have to pay "import tax" on it. Great....Can I have my Spanish plates now? No....we had to return to our local Hacienda to get them to rubber stamp a form to say we DID NOT have to pay import tax (despite having all the proof with us at Malaga), then bring the form back to Malaga so they could check it .......this just went on and on and on.
When we brought the car back to UK and went to change it back to UK plates, we went to the local DVLA office, expecting a work up and a bill. We filled in a form, put our UK plates back on ....and guess what they charged???? NOTHING....it's free in UK