Posted: Thu Mar 21, 2019 9:09am
No.
Re-registration in Spain gets the car a Spanish identity. It is taxed and tested in Spain (An MOT is called an ITV here).
Step 1 - present the car at an ITV station, with the British V5 document. Most cars don't have LHD/RHD switchable headlights, so they fail. But the failure notice lists the necessary remedial work. The rear lights sometimes need minor modifications. They will also do the normal safety stuff (brakes, seat belts, rust checks etc), and they don't like modified cars. You get 2 months to correct any issues. They keep the V5, so make a copy before you go.
Step 2 - when the work is done, take the car back to the ITV station for the sign-off. As long as you take it back within 2 months, they only re-check the listed items. Assuming it passes, you get the V5 back, and a new Spanish "matriculation" document that enables you to progress to Step 3. Steps 1 and 2 cost around 230 Euros in total.
Step 3 - you will probably need a gestor to help with this ... the new documentation (and the V5) goes to the tax office, and an import tax is paid. You then get the full set of Spanish registration documents, and your car is Spanish. From memory, you don't get the V5 back (I assume the Spanish authorities notify the DVLA in the UK - not sure). The cost of step 3 depends on the age/value/pollution rating of the car.
One thing I learnt ... I left it a bit late for one of our cars. It took it for step 1 about 2 weeks before the UK MOT ran out. It took nearly 2 months to complete step 2. The car had been modified from standard, and it took some time to get the parts to re-standardise it, and the Christmas holidays got in the way. The car failed at step 1, and the failure notice specified that the car could only be driven between my home, my mechanic and the ITV station. So once my UK MOT ran out, the car was grounded.