Now I see that you´re using some English frases which not much spaniards will understand....
VAT = IVA and MOT = Impuesto de vehiculos.
I first thought you were Spanish, but it appears you´re not, or are you?
Anyway, I´ll continue in English.
This company is used to export campers to all of Europe, so they´ll provide you with all the necesary papers and numberplates to get to Spain.
They´ll not do the importing to Spain for you i think. So with all the paperwork you´ll have you need to pass by at some tecnical inspection station (the "ITV") and "Trafico" (that´s the local ministry of traffic and motorized vehicles). Youll have to pay for the tecnical inspection and some taxes too at "Trafico". Then you have to buy the new numberplates. Because your camper will be new and have all the neccesary papers for a european homologation there really cannot be much problems.
I just assumed you wanted to buy a new camper but if that´s not the case, you´ll have to be very careful.
Don´t buy anything older than 1996. These campers don´t have a proper European registration number and it can take up to a year to registrate them in Spain, besides you´ll have to spent a lot of money.
If you´re buying a second hand camper newer than 1996, be sure there is a european registration number somewhere in the papers. There should be, but just make sure. The rest is the same as with a new camper only you need the paperwork to export the camper out of Germany. That´s not very complicated, but means more work and time than with a new one from a company that is specialized in export. Anyway there are more second-hand camper suppliers that know what to do with export, only the smaller ones and private sellers won´t know anything about it.
Well, just ask if you want to know more, regards.