Patrick, see this link: www.eyeonspain.com/forums/posts-long-2458.aspx
I remember asking this question before, when we were thinking of bringing a car from Dubai. Don't know if anything has changed. Also, the company you are using to ship your belongings should provide information on car import also. We used Crown when we moved here in September and they provided all this sort of info, although I still asked the question re import duty.
I bought a car in Dubai in February this year (a top of the range LR2 to give you an idea of value) from a guy in Dubai who was moving to Fuengirola and he said that he could have imported it into Spain for about 10,000 Euros, but had decided to sell it. He had owned it for a year.
I also recall a friend of a friend who imported a Jag from Dubai to Spain and it cost them dearly - had they decided to import it to the UK and then bring it over from there it would have cost them alot less, apparently.