I haven't tried putting three - across in the back row, but I have heard that it's possible
with narrow car seats, despite the seats being more stationary.
We use these with
our narrow car seat to get them all the way into their seat on the airplane.
If I remember correctly we may not have gotten
the narrow car seat right away, so it might not even have been needed.
When my third was born, 20 months after my second, we had a Kia Sorento and bought one car seat for my oldest that was marketed as
a narrow car seat.
With a width of only 17 inches, it is one of
the narrowest car seats on the market, making it an easy seat to fit into any vehicle.
The Marathon is
another narrow car seat at only 18.5 inches wide.
But if you need something for little ones on car trips only and you have
a narrow car seat, we thought it worth mentioning here.