Smallest car possible (the size road-spacing advantage also means it could be cheaper).
Manual transmission isn’t a disadvantage (this, coming from someone who’s driven several stick-shift cars at home, even now, and both my husband and I are left-handed). Many others insist on an automatic.
The person in the front passenger-side (left) seat should be the navigator, alerting the driver to the next upcoming turn/roundabout in “x” kilometers, then reminding as that feature gets closer. Person should also remind the driver on a regular basis to not get too far to the left, where stone walls and/or a shoulder drop-off might exist. Reaffirming speed limit signs, too.
On two-lane roads (road numbers will usually start with a letter “L” or “R”), anticipate that there will be curves and or hills where you can’t see around or over, and expect that something BIG will be appearing in a moment, coming at you. If it’s a tractor, get waaaaay to the left (remembering that your navigator just said not to get too far left), take a deep breath, and hold on. You may want to slow down, but the tractor will not!
On extremely narrow roads, when it’s barely wide enough for two vehicles, be prepared to come to a stop. The oncoming vehicle will (or, at least, should) stop too, so that the two of you can ease by each other. That may require further adjustments to accommodate side-view mirrors or dimensions of the larger vehicle. You’ll appreciate (and be appreciated for) having the smaller one.
At roundabouts, if you’re ultimately going to the right (a three o’clock position, if you’re coming from the six o’clock direction), don’t make an immediate right as you reach the roundabout. You need to keep to the left, to the far side of the roundabout, then curve right towards your exit.
Highway exits will have a sign before you reach the exit, indicating which lane will get you to which direction. Get lined up accordingly. There may well be a multi-lane roundabout at that exit, which requires particular attention.
In a small roundabout on a small road, if you miss an exit, stay in the roundabout and go around again, giving you a second chance to determine your correct exit.
Really big roundabouts on big “A” highways are much more complicated, and are less forgiving if you miss an exit the first time, so be prepared before you reach it.
Take breaks, as needed - or even before they’re absolutely needed.
Familiarize yourself with the windscreen (windshield) wiper controls before you get a rainstorm. And yet, don’t be surprised if when you want to signal a lane-change or a left or right turn, you wind up activating the wipers! LOL
Watch for big, medium-brown signs with white lettering. They’ll advise of interesting sights ahead, maybe something you hadn’t expected, but that you might love. That’s how we discovered the wonderful Gougane Barra lake and hiking trails in County Cork.
Driver may be focusing on driving (rightfully so), but could be missing out on outstanding scenery. Will different people be driving, to allow everybody a chance to be a spectator? If not, pull off more often, for views!
This is an unwritten rule, but from our last trip in 2024, seems to be an Absolute Truth - the biggest bullies on the roads in Ireland seem to be driving an Audi. Not all Audi drivers are inconsiderate, but if a car zips by you then cuts you off, won’t let you in or change lanes, or tailgates, it’s likely to be an Audi. Not sure why, but maybe certain people in Ireland also are attracted to Audi’s.