I wonder though how the Spanish (or any other EU authorities) can precisely tell how many days you spend in a specific country. It would be a daunting task. Ok when you leave Ireland indeed you do get the passport scanned etc. but once you are outside of Ireland within the Schengen area nobody checks your passport any more. Eg. when I go back home to France I could drive or take a train to Italy, Switzerland, Austria, Germany, Spain and many more places and I did it many times and nobody has ever stopped me and asked to show my ID when crossing these borders.