6 nights, 7 days trip to Ireland

Is the 6 nights including your arrival and departure day? If so, then you are really short on time and I would suggest not going too far from Dublin. Perhaps head north or south, but you don’t want to spend all your time behind the wheel of a car.
I can say having driven in Ireland myself, easy peasy. On the narrow roads, people drive slower. You will have the hang of it in no time. I adapted so well, that when I returned home, I found myself heading to the drivers side on the right!

As far as must see sights.....an oft quoted sentiment on this forum, but what it means to you and what it means to me, could be vastly different. Please give more info as to your interests.

Thanks we arrive on Sunday morning around 5 am and depart next Saturday around 11:30 AM. I was looking something like https://goingawesomeplaces.com/southern-ireland-ultimate-guide-7-day-road-trip-itinerary/ but wanted to make modifications.

Well the day you arrive I would spend that night in Dublin , taking in driving on the “ wrong “ side of the road while likely tired and jet lagged is not a good idea .

I don’t know if I’d bother renting a car myself - you should spend Friday night back in Dublin anyways to get your flight Saturday morning . So that basically only leaves you a few days to tool around with - bus or train to Galway or Kilkenny is what is what I would look at .

A daytrip from Dublin we really enjoyed is visiting Newgrange and the hill of Tara - we took a Mary Gibbons bus tour there , very interesting . We also took “ Rural Pub Tour “ from Dublin ( as opposed to doing one in town - where you can just walk around yourself and do it ) , the Rural Pub Tour takes you out into countryside , to small neighbors type pubs - small group ( not a big bus more like a 15 passenger van ) great tour guide !

Who is "we"? Are you traveling as a couple or as a family?
In March you'll be well ahead of the tourist crush that starts around the first of June, which is a good thing. The tradeoff however is that the weather can be pretty gloomy then - daily highs barely into the 50's and not much sun.
You don't say where you're coming from but if you're landing in Dublin at 5 AM it's a pretty safe bet that you'll arrive tired, probably sleepless after the overnight flight, and jetlagged. If your budget permits you might consider booking a room in Dublin for the night before so that it's "ready on arrival". Works for us anyway. We find it well worth the cost to grab a shower and a nap before waking refreshed and ready for an active day.
Given your limited time I agree that a car may not be necessary. There are plenty of day trips from Dublin that will keep you occupied for several days, and there's always the short train ride up to Belfast - a fascinating and beautiful city. The Titanic Quarter (the old Harland & Wolfe shipyard area) has been a recent subject of urban renewal and redevelopment and is now a very nice place to base yourselves for a day or two. Can also book day trips from there up to Derry and the Causeway Coast.
A good choice for another base not requiring a car would be Galway - a 2 hour train or bus ride from Dublin. There are a number of day trips available there too that might be of interest: to the Burren and the Cliffs, around the beautiful Connemara Loop, including the Sky Road west of Clifden, and the ferry out to the Aran Islands. Aran Ferries has a pickup point right in Galway to get you out to the landing at Rossaveal - well worth a day of your time if it's a sunny day.

As someone else suggested I don't think I would bother renting a car with the limited time you have. You can split your time between Dublin and Galway and make use of some guided day trips to see some of the main sights and not have the worry of learning to drive on the left. Spend the day you land in Dublin seeing some things in the city, and then you could use the next day or two to do guided day trips out of Dublin (Newgrange and Glendalough are favourites). Then take the train to Galway and do the same thing there before returning to Dublin to fly home. This will simplify things for you, and be less stressful if you are worried about the driving yourself.

I driven the island twice solo and was born when Truman was in office but I also dwell in LA where your life is spent in your car.

That said for the short amount of time you will have best to punt the idea of car travel and book day trip tours out of Dublin and ( hold on ) spend a day in a separate country called Northern Island.

Intinerary:
Day 1 - arrive Dublin, get settled, walk in St Stephens green and meander about Grafton Street. Get a good nights rest.

Day 2 - take a pre arranged tour to Glendalough and Powerscourt

Day 3- take a pre arranged Mary Gibbons tour to visit Newgrange and the Hill Of Tara

Day 4 - visit the Book of Kells at Trinity College and the Guinness Brewery.

Day 5 - take the train or bus North to Belfast. In Belfast fine an ATM and withdraw a few pounds then take the Black Cab troubles tour, visit The Crumblin Road Gaol and the Titanic Museum

Day 6 - just meander about Dublin. Take the river walk, have some good fresh seafood, shop and if weather is miserable find a pub and meet the locals.

Slainte

Agree with day trip to Belfast if nothing else but the Black Cab tour it was one of the best things we did in the north. You do need pounds not euros. I personally would skip Guinness and do Kilmainhaim Gaol have been there 3 times and it still amazes me but I believe now you need advance tickets however we went off season and 9 of us maybe just got lucky but we were just able to do walk up and get tickets. Enjoy this fantastic country.

Hi Sam.

Ive visited Ireland on a number of occasions, and have rented a car, taken public transport and also used a private tour company. Don't be nervous about driving on the wrong side of the road, its a piece of cake. Sure the roads are narrow, but the cars are also quite narrow. Just take your time and you'll be fine.

Id recommend booking your accommodation before to arrive, especially if you are going to be there anytime near St Patricks day. it will work out cheaper anyway if you book in advance.

Id take my time and drive west from Dublin stopping in the midlands in Athlone or maybe Longford. Id suggest spending your time visiting the wonderful west coast including Cong, Galway, Aran Islands, Lahinch and Tralee.

Its all beautiful so you wont be disappointed.

Hope this helps a bit.

Mike.