I was faced with a broadly similar situation with my huge Yank Tank Motorhome.
Firstly SORN is not an option. Although you will not find any reference to this particular sub-clause on the DVLA website, DVLA will tell you that a SORN can only be applied to a vehicle which is physically in the UK; My particular vehicle was off road on a private campsite in Spain, was incapable of being driven because of engine and other problems, and running up non-payment of UK Road Tax fines. We couldnt get it back to the UK because even if we had been in a position to get it fixed, the UK MOT had expired and in order to drive the thing back to England we would have needed an MOT cert to legally drive it acrossSpain and France.
Couldnt get road tax because of no MOT, couldnt get an MOT because that required the vehicle to be in England. DVLA were totally unsympathetic to our case and just sent another non payment fine to our English forwarding address. Eventually a local Spanish garage 'took the vehicle off our hands' for a stupidly low figure, about 10% of its true value but we were so pig sick of the whole situation that we were just glad to see the back of it!
Sompting... One of the measures we considered was scrapping the vehicle in Spain and it appears not to be a problem. If you really need to go this route...Detach the scrapping section from the vehicles V5 document and hang on to it. Take the vehicle to a local Desguace along with the rest of the V5 and hand the vehicle over to them. They will issue a 'Certificate of Destruction.'
Send a copy of the Cerificate along with the scrapping section from the V5 to DVLA and thats an end to it. A quick check of Desguaces in Extramadura shows several in the usual places Caceres, Badajos and Trujillo.See Spanish Yellow Pages (link). If your Sapnish is really limited put Desguaces under 'Actividades' Extremadura under 'Provincias' and your location under Localidad; leave 'Nombre de Empresa' blank. Click on 'Encontrar.' and see what comes up...
Consider first though the action of scrapping the van...
Spain without a car can be a lonely place particularly if you have no friends close to hand.
A replacement vehicle will cost a hell of a lot more than in the UK.
Second hand prices over here are considerably higher than back home anywhere between 30% and 50% higher.
Five minutes on a rolling road at a main Citroen agent will tell you all you need to know about whats mechanically wrong with the brakes and you dont necessarily need to get it repaired at a main agent. Many smaller garages will gladly take on the work involved. Get a quote from a main agent and a smaller garage once you know just what the problem is. Chances are its something very simple and easily fixed.
Citroen Dispatch vans are very common over here and to the best of my knowledge perfectly straightforward mechanically; not like the XM series of cars with their all hyraulic brakes steering and suspension.
Quote 'The van is a panel van, but there is the option to change the two sliding side doors to ones with windows. We did consider this but didn't know if this would then enable us to get the van changed to Spanish plates or not, as the registration document would still show it as a light goods vehicle.unquote
I cannot comment on the viability of relacing the side doors with the windowed version. I would imagine this would have to be done by Citroen to meet Homulgation requirements in Spain. The Authorities are incredibly hot on seemingly minor things when it comes to ITV (MOT) requirements and an ITV would be the first thing they would need to see...It isn't cheap to re-register onto Spanish plates especially if your Spanish isn'tso hot...Best to engage the services of a Gestor for this.
So far as the UK reg document and description is concerned if the vehicle is re-registered in Spain, the UK documentation would be meaningless as a fresh Spanish Document would be issued...Bear in mind also the other primary requirements for re-registration such as headlights which need to deflect to the right not the left; if a single fog light is fitted on the right side of the vehicle it needs to be moved to the left; some authorities will insist that the speedo is replaced with one showing Km/Hr as the primary reading rather than secondary.
The six month rule is one of the major problems facing drivers of UK reg vehicles as is so evident particularly on the Costas where their are many totally illegal vehicles without UK Road Tax or MOT certs and hence no insurance.
Somewhat cynically I tend now to check the vehicle of any Brit tradesman who comes to my house. If he is driving a UK reg vehicle and not displaying a valid UK Road Tax disc he doesn't get the work; my point of view being that if he is prepared to play fast and loose with the Spanish Police, the chances are he will take the same liberties with me. (Too many experiences with Brit Vaqueros or cowboys...)
Incidentally, one way of getting along language wise with problems of communication with traders, garages is to write down what you want to say, in short sentences, in English and then feed this into babelfish (link) for a literal translation. The sentence formation of the translation may not be correct but its sufficiently accurate to put your question across. If you can get your trader to write down his response if it isnt clear you can always use babelfish in reverse to get it back into English.
Hope some of this helps...