Hi Martin, there are many opinions about bringing cars to Spain and all valid and every option should be considered as information before your move is 'Everything'. In my case, I decided to buy a LHD car in the UK and have it registered her in Spain. As we have a dog we decided to drive from the UK via LeShuttle to Pinoso (Alicante). There are a few LHD dealers in the UK and the cars are at a reasonable price, certainly if you bought the same car in Spain you would be paying a few more thousand euros. Even with ITV (MOT), registration and tax it still works out a sensible option, especially if you want to drive a better model of car. As soon as you are through the euro tunnel you are driving on the right and believe me having a LHD car really helps and my advice.... also get an automatic, changing gear with your right hand takes some getting used to. Oh I am sure there will be plenty of readers out there itching to put me right but that is what I think!
I purchased a Mercedes ML320 3L Automatic - 'Hold it everyone, I can feel you all waiting to shout at your screens' but it does have a low emission figure and Tax has been calculated at only 495 Euros. The drive over which took 3 days with stops was made so much easier with this car and having driven here in Spain for a few days it was definitely the right decision for us.
HOWEVER - I made the mistake of thinking that it would be easy to get insurance for the trip and our stay in Spain until we had the ITV and Spanish registration and would have been if it was a UK or Spanish registered car! The 'Beast' as we affectionately call it, was still on Belgium plates and we purchased it not knowing the issue. After a lot of panic and everyone refusing us insurance, our dealer finally sorted out limited 2 week insurance via Holland. I have extended this to 4 weeks and now must have the car registered in Spain asap to get insurance.
So, my advice... Look at LHD cars in the UK that suits your needs, make sure it is UK or Spanish registered, the car has a full log book, serviced and MOT (although the MOT does not count here in Spain but will give you some confidence and needed whilst driving in the UK), if it has a tow bar you may need to remove it or you may need a manufacturers authentication letter for the ITV, get the car Spanish registered as soon as you arrive as you may get a tax reduction. If the car comes with a Certificate of Conformity all the better but not essential.
I AM NOT AN EXPERT AND JUST SHARING MY EXPERIENCE AND ADVICE TO HELP IF I CAN.
Regards Paul