You have to import it within 6 months of your arrival/the cars arrival into spain. You also have strict time limits form yoru first registration on the padron otherwise you will have ot pay import tax (not sure how long this is, 2 3 or 6 months). Google spanish car imports or something and there are many specialist companies. Otherwise just look in any town and you will see tons of Gentoria offices who will do it all for you!Spain will be my country of residance from now on and for the foreseable future, where can you look into a gestor about??
Expect to pay anything from 500 to 1000 euros though pls any taxes that may be due depending on your circumstances, how long you have been here, how long you have had the car etc.
Theres loads of other threads on this forum about cars so you should get a lot of info on here!