We just reurned from staying six days at Adare Manor Villas for $599 including car - a very good deal UNTIL you factor in $89 each for an upgrade for an automatic with a GPS AND 360 Euros for insurance from Dooley's Car Rental. That works out $140 PER DAY for the car.
Do not do the upgrade. The GPS is not worth it - signage in Ireland is very good (and in English). The free meal was forgettable.
Go to the next kiosk at the airport (or online) and arrange for your own 4 passenger rental car with automatic for around 40 euros per day (quote from Thrifty).