We have just moved from Tarragona to Malaga and have completed all our paperwork changes except for the Car Documentation and are not sure what is do here. (The garage arranged everything when we bought the car!)
Can anyone advise, please?

Time for a trip to traffico

start here

http://www.dgt.es/portal/es/oficina_virtual/conductores/cambio_domicilio/

http://www.dgt.es/portal/es/oficina_virtual/vehiculos/cambio_domicilio/?tit=?D?nde se puede solicitar?

or go to a gestor and let them do it all for you.

Thanks Rob. Much appreciated.