Neil, I have taken this new from aeromadrid web page:
"The DAEMUR society and Aero Madrid SA has subscribed an agreement of collaboration with the purpose of initiating programs of aeronautical education in the Airport of San Javier. These activities have had a great acceptance on the part of the Murcian Community as well as by the Polytechnical University of Cartagena"
But as far as I know, AeroMadrid do not rent aircrafts without instructor !
I suggest you to check Aeroway reputation in the Spanish forums...
Best Regards
Ignacio