Thanks all for comments...
Regarding Super Valu carpark, yes I have considered that, but there are signs up saying that cars other than customers will be clamped.
Anyway on the other front, things have developed in the meantime, so I think I'll be taking the car into the city centre from now on and looking for free parking around the summerhill area.
Using the train is a no win situation... and the financial benefits after paying for tickets AND parking are minimal at best when compared with running the car.
I did try to use public transport - but IE have won the battle
If I ever meet John Gormley and he starts ranting on about increasing motor taxes and getting people to use public transport, I'll have a few suggestions for him.