I recommend you get ownership transfered in you name asap and I have used Zamora in Mazarron (Twice) they are very good you will of course have to pay the transfer fee.
Best get it ITV in Spain as soon as you transfer.
Normally when you buy a Spanish car the seller attends the Gestor with the buyer.
If you are insured you can drive the car but the previous owner cops the fines till you transfer.
If car is Spanish registered you can not put MOT on it will not be valid.
Suggest if car is in Spain you hire a car foir two days then you can do ITV and Transfer and then you are all legal
From your post you can drive it till ITV expires and as long as you are insured.
Tax runs from 1st Jan to 31st Dec and whoever owns the vehicle on 1st Jan is liable for that year so its quite common to buy a car in may and not pay tax till following year.
Part of transfer ensures you pay tax for following year. Alama is about 90€ year for a 1.7 Deisel
This message was last edited by Sonatigh on 09/05/2013.