we've got a holiday cottage booked in Donegal for the first week of July; we want to extend that by 2-3 nights in Dublin town, preferably near but not too near the centre, and ideally with parking although I appreciate that might be a long shot.
Taking our own car, Cairnryan - Larne, drive across NI to Donegal, then drive down to Dublin, short break, then drive back to Larne for the return ferry. Or maybe come back Dublin /Dun Laoghaire - Holyhead/Liverpool. not decided yet, 2 hour crossing up top, but long drive to Stranraer, or long crossing & shorter drive.
So no pitiful 15kg airline baggage allowance or hire car costs to worry about