Hi Helen
Online website http://www.itvcita.com/accesoSolicitudCitaPaso1.do
Matrícula: is the Car Registration Number for example 2159RWS
Fecha de Matriculación
(dd/mm/aaaa): is the date of first registration in the Car's Green Log Book
Input these two values in this website and then Suggested Date ,Location and time will come up. Confirm Location Date and change time ,if necessary,. Then confirm the Booking and a new page will come up quoting your Car Registration Number ,ITV Testing Station ,Date of Test and Reference Code. Print off this confirmation and take to ITV Station on day of Test.