Also have an 18 Accord with 3, although ours are a bit older. I very rarely have all 3 in my car, so worst case the 8 year old sits in the middle seat for the mile drive from school.
Have heard/read good things about these:
https://a.co/d/fP78hm6
Diono Radian 3R
Have heard/read good things about these:
https://a.co/d/fP78hm6
Diono Radian 3R