Road tripping overseas with children adds a few extra considerations, mostly around car seats and trip pacing.
Car seat laws vary by country, and rental agencies may or may not stock the size you need, so it's often worth traveling with your own lightweight, travel-friendly seat. Confirm the local age and height requirements ahead of time so you're not caught off guard at pickup.
Build more stops into your itinerary than you would on a solo trip. Younger children generally do best with a travel day broken into two-to-three-hour driving blocks with playground or snack breaks in between.
Pack entertainment that doesn't rely on a data connection, since you may lose signal in rural or mountainous areas, and bring basic snacks and water in case stops are farther apart than expected.