Exporting car from Spain to UK on behalf of my Grandad

Hope somebody can help as ive been reading the forums and the .gov.uk sites but cant really get a straight forward answer.

My grandad, who has lived out in Spain for about 3 years has come back 'home' to the UK as he is in the final stages of his life owing to Cancer.  He would like his car, which is about 4 years old and has spanish plates (RHD UK car transferred over) to be brought home, with his few personal belongings inside.

I offered to drive his car home for him, as he isnt fit enough to drive it at the moment.  Its looking like a drive throgh france as ferrys from spain to uk are fully booked over bank holiday weekend (30 aug).  The drive isnt a problem, but was wondering what the procedures in spain are for de registering his car thre as he wont be with me, insurance requirements (i have full uk licence clean), Also i read that you cant drive a spanish registered car in the uk with a uk licence. is that true or as im not the registered owner make a difference?

Does anybody have any experience of this?

Thanks in advance

Contact DVLA.       Also check out this link.......assuming it is okay that I put it on this site.

http://britishexpats.com/forum/spain-75/changing-my-spanish-plates-back-uk-plates-690755/page2/

That info is too old to be pf any use and posting the link appears to be against this rule:- 

NO LINKS TO EYE ON SPAIN "COPYCAT" WEBSITES - We get it all the time.  People have realised what a great facility we've developed here and many people have chosen to copy us.  They then decide that they will come to Eye on Spain and steal the members we've worked so hard for over 8 years.  No thank you, you're not welcome here.

Well, let's hope this link is in date and legally allowed on this site without fear of people poaching....

https://www.gov.uk/importing-vehicles-into-the-uk